Microsoft Defender Security Research has observed a widespread phishing campaign leveraging the Device Code Authentication flow to compromise organizational accounts at scale. While traditional device code attacks are typically narrow in scope, this campaign demonstrated a higher success rate, driven by automation and dynamic code generation that circumvented the standard 15-minute expiration window for device codes. This activity aligns with the emergence of EvilToken, a Phishing-as-a-Service (PhaaS) toolkit identified as a key driver of large-scale device code abuse.

This campaign is distinct because it moves away from static, manual scripts toward an AI-driven infrastructure and multiple automations end-to-end. This activity marks a significant escalation in threat actor sophistication since the Storm-2372 device code phishing campaign observed in February 2025.

• Advanced Backend Automation: Threat actors used automation platforms like Railway.com to spin up thousands of unique, short-lived polling nodes. This approach allowed them to deploy complex backend logic (Node.js), which bypassed traditional signature-based or pattern-based detection. This infrastructure was leveraged in the attack end-to-end from generating dynamic device codes to post compromise activities.
• Hyper-personalized lures: Generative AI was used to create targeted phishing emails aligned to the victim’s role, including themes such as RFPs, invoices, and manufacturing workflows, increasing the likelihood of user interaction.
• Dynamic Code Generation: To bypass the 15-minute expiration window for device codes, threat actors triggered code generation at the moment the user interacted with the phishing link, ensuring the authentication flow remained valid.
• Reconnaissance and Persistence: Although many accounts were compromised, follow-on activity focused on a subset of high-value targets. Threat actors used automated enrichment techniques, including analysis of public profiles and corporate directories, to identify individuals in financial or executive roles. This enabled rapid reconnaissance, mapping of permissions, and creation of malicious inbox rules for persistence and data exfiltration.

Once authentication tokens were obtained, threat actors focused on post-compromise activity designed to maintain access and extract data. Stolen tokens were used for email exfiltration and persistence, often through the creation of malicious inbox rules that redirected or concealed communications. In parallel, threat actors conducted Microsoft Graph reconnaissance to map organizational structure and permissions, enabling continued access and potential lateral movement while tokens remained valid.

Attack chain overview

Device Code Authentication is a legitimate OAuth flow designed for devices with limited interfaces, such as smart TVs or printers, that cannot support a standard interactive login. In this model, a user is presented with a short code on the device they are trying to sign in from and is instructed to enter that code into a browser on a separate device to complete authentication.

While this flow is useful for these scenarios, it introduces a security tradeoff. Because authentication is completed on a separate device, the session initiating the request is not strongly bound to the user’s original context. Threat actors have abused this characteristic as a way to bypass more traditional MFA protections by decoupling authentication from the originating session.

Device code phishing occurs when threat actors insert themselves into this process. Instead of a legitimate device requesting access, the threat actor initiates the flow and provides the user with a code through a phishing lure. When the user enters the code, they unknowingly authorize the threat actor’s session, granting access to the account without exposing credentials.

Phase 1: Reconnaissance and target validation

 The threat actor begins by verifying account validity using the GetCredentialType endpoint. By querying this specific Microsoft URL, the threat actor confirms whether a targeted email address exists and is active within the tenant. This reconnaissance phase is a critical precursor, typically occurring 10 to 15 days before the actual phishing attempt is launched.

The campaign uses a multi-stage delivery pipeline designed to bypass traditional email gateways and endpoint security. The attack begins when a user interacts with a malicious attachment or a direct URL embedded within a high-pressure lure (e.g., “Action Required: Password Expiration”).

To evade automated URL scanners and sandboxes, the threat actors do not link directly to the final phishing site. Instead, they use a series of redirects through compromised legitimate domains and high-reputation “Serverless” platforms. We observed heavy reliance on Vercel (*.vercel.app), Cloudflare Workers (*.workers.dev), and AWS Lambda to host the redirect logic. By using these domains, the phishing traffic “blends in” with legitimate enterprise cloud traffic, preventing simple domain-blocklist triggers.

Once the targeted user is redirected to the final landing page, the user is presented with the credential theft interface. This is hosted as browser-in-the-browser (an exploitation technique commonly leveraged by the threat actor that simulates a legitimate browser window within a web page that loads the content threat actor has created) or displayed directly within the web-hosted “preview” of the document with a blurred view, “Verify identity” button that redirects the user to “Microsoft.com/devicelogin” and device code displayed.

Below is an example of the final landing page, where the redirect to DeviceLogin is rendered as browser-in-the-browser.

The campaign utilized diverse themes, including document access, electronic signing, and voicemail notifications. In specific instances, the threat actor prompted users for their email addresses to facilitate the generation of a malicious device code.

Unlike traditional phishing that asks for a password, this “Front-End” is designed to facilitate a handoff. The page is pre-loaded with hidden automation. The moment the “Continue to Microsoft” button is clicked, the authentication begins, preparing the victim for the “Device Code” prompt that follows in the next stage of the attack.

The threat actor used a combination of domain shadowing and brand-impersonating subdomains to bypass reputation filters. Several domains were designed to impersonate technical or administrative services (e.g., graph-microsoft[.]com, portal-azure[.]com, office365-login[.]com). Also, multiple randomized subdomains were observed (e.g., a7b2-c9d4.office-verify[.]net). This is a common tactic to ensure that if one URL is flagged, the entire domain isn’t necessarily blocked immediately. Below is a distribution of Domain hosting infrastructure abused by the threat actor:

Phase 2: Initial access

The threat actor distributes deceptive emails to the intended victims, utilizing a wide array of themes like invoices, RFPs, or shared files. These emails contain varied payloads, including direct URLs, PDF attachments, or HTML files. The goal is to entice the user into interacting with a link that will eventually lead them to a legitimate-looking but threat actor-controlled interface.

Phase 3: Dynamic device code generation

When a user clicks the malicious link, they are directed to a web page running a background automation script. This script interacts with the Microsoft identity provider in real-time to generate a live Device Code. This code is then displayed on the user’s screen along with a button that redirects them to the official microsoft.com/devicelogin portal.

The 15-Minute race: Static vs. dynamic

A pivotal element of this campaign’s success is Dynamic Device Code Generation, a technique specifically engineered to bypass the inherent time-based constraints of the OAuth 2.0 device authorization flow. A generated device code remains valid for only 15 minutes. (Ref: OAuth 2.0 device authorization grant). In older, static phishing attempts, the threat actor would include a pre-generated code within the email itself. This created a narrow window for success: the targeted user had to be phished, open the email, navigate through various redirects, and complete a multi-step authentication process all before the 15-minute timer lapsed. If the user opened the email even 20 minutes after it was sent, the attack would automatically fail due to the expired code.

Dynamic Generation effectively solves this for the threat actor. By shifting the code generation to the final stage of the redirect chain, the 15-minute countdown only begins the moment the victim clicks the phishing link and lands on the malicious page. This ensures the authentication code is always active when the user is prompted to enter it.

Generating the device code

The moment the user is redirected to the final landing page, the script on the page initiates a POST request to the threat actor’s backend (/api/device/start/ or /start/). The threat actor’s server acts as a proxy. The request carries a custom HTTP header “X-Antibot-Token” with a 64-character hex value, and an empty body (content-length: 0)

It contacts Microsoft’s official device authorization endpoint on-demand and provides the user’s email address as hint. The server returns a JSON object containing Device Code (with a full 15-minute lifespan) and a hidden Session Identifier Code. Until this is generated, the landing page takes some time to load.

Phase 4: Exploitation and authentication

To minimize user effort and maximize the success rate, the threat actor’s script often automatically copies the generated device code to the user’s clipboard. Once the user reaches the official login page, they paste the code. If the user does not have an active session, they are prompted to provide their password and MFA. If they are already signed in, simply pasting the code and confirming the request instantly authenticates the threat actor’s session on the backend.

Clipboard manipulation

To reduce a few seconds in 15-minute window and to enable user to complete authentication faster, the script immediately executes a clipboard hijack. Using the navigator.clipboard.writeText API, the script pushes the recently generated Device Code onto the victim’s Windows clipboard. Below is a screenshot of a campaign where the codes were copied to the user’s clipboard from the browser.

Phase 5 – Session validation

Immediately following a successful compromise, the threat actor performs a validation check. This automated step ensures that the authentication token is valid and that the necessary level of access to the target environment has been successfully granted.

The Polling

After presenting the code to the user and opening the legitimate microsoft.com/devicelogin URL, the script enters a “Polling” state via the checkStatus() function to monitor the 15-minute window in real-time. Every 3 to 5 seconds (setInterval), the script pings the threat actor’s /state endpoint. It sends the secret session identifier code to validate if the user has authenticated yet. While the targeted user is entering the code on the real Microsoft site, the loop returns a “pending” status.

The moment the targeted user completes the MFA-backed login, the next poll returns a success status. The threat actor’s server now possesses a live Access Token for the targeted user’s account, bypassing MFA by design, due to the use of the alternative Device Code flow. The user is also redirected to a placeholder website (Docusign/Google/Microsoft).

Phase 6: Establish persistence and post exploitation

The final stage varies depending on the threat actor’s specific objectives. In some instances, within 10 minutes of the breach, threat actor’s registered new devices to generate a Primary Refresh Token (PRT) for long-term persistence. In other scenarios, they waited several hours before creating malicious inbox rules or exfiltrating sensitive email data to avoid immediate detection.

Post compromise

Following the compromise, attack progression was predominantly observed towards Device Registration and Graph Reconnaissance.

In a selected scenario, the attack progressed to email exfiltration and account persistence through Inbox rules created using Microsoft Office Application. This involved filtering the compromised users and selecting targets:

• Persona Identification: The threat actor reviewed and filtered for high-value personas—specifically those in financial, executive, or administrative roles—within the massive pool of compromised users.
• Accelerated Reconnaissance:  Using Microsoft Graph reconnaissance, the threat actor programmatically mapped internal organizational structures and identify sensitive permissions the moment a token was secured.
• Targeted Financial Exfiltration: The most invasive activity was reserved for users with financial authority. For these specific profiles, the threat actors performed deep-dive reconnaissance into email communications, searching for high-value targets like wire transfer details, pending invoices, and executive correspondence.

Below is an example of an Inbox rule created by the threat actor using Microsoft Office Application.

Mitigation and protection guidance

To harden networks against the Device code phishing activity described above, defenders can implement the following:

• Only allow device code flow where necessary. Microsoft recommends blocking device code flow wherever possible. Where necessary, configure Microsoft Entra ID’s device code flow in your Conditional Access policies.
• Educate users about common phishing techniques. Sign-in prompts should clearly identify the application being authenticated to. As of 2021, Microsoft Azure interactions prompt the user to confirm (“Cancel” or “Continue”) that they are signing in to the app they expect, which is an option frequently missing from phishing sign-ins. Be cautious of any “[EXTERNAL]” messages containing suspicious links. Do not sign-in to resources provided by unfamiliar senders. For more tips and guidance – refer to Protect yourself from phishing | Microsoft Support.
• Configure Anti-phising policies. Anti-phishing policies protect against phishing attacks by detecting spoofed senders, impersonation attempts, and other deceptive email techniques.
• Configure Safelinks in Defender for Office 365. Safe Links scanning protects your organization from malicious links that are used in phishing and other attacks. Safe Links can also enable high confidence Device Code phishing alerts from Defender.
• If suspected device code phishing activity is identified, revoke the user’s refresh tokens by calling revokeSign-inSessions. Consider setting a Conditional Access Policy to force re-authentication for users.
• Implement a sign-in risk policy  to automate response to risky sign-ins. A sign-in risk represents the probability that a given authentication request is not authorized by the identity owner. A sign-in risk-based policy can be implemented by adding a sign-in risk condition to Conditional Access policies that evaluates the risk level of a specific user or group. Based on the risk level (high/medium/low), a policy can be configured to block access or force multi-factor authentication.
  • When a user is a high risk and Conditional access evaluation is enabled, the user’s access is revoked, and they are forced to re-authenticate.
  • For regular activity monitoring, use Risky sign-in reports, which surface attempted and successful user access activities where the legitimate owner might not have performed the sign-in. 

Microsoft recommends the following best practices to further help improve organizational defences against phishing and other credential theft attacks:

• Require multifactor authentication (MFA). Implementation of MFA remains an essential pillar in identity security and is highly effective at stopping a variety of threats.
  • Leverage phishing-resistant authentication methods such as FIDO Tokens, or Microsoft Authenticator with passkey. Avoid telephony-based MFA methods to avoid risks associated with SIM-jacking.
  • Block legacy authentication with Microsoft Entra by using Conditional Access. Legacy authentication protocols do not have the ability to enforce MFA, as legacy MFA (per-user MFA prompts) is susceptible to abuse.
• Centralize your organization’s identity management into a single platform. If your organization is a hybrid environment, integrate your on-premises directories with your cloud directories. If your organization is using a third-party for identity management, ensure this data is being logged in a SIEM or connected to Microsoft Entra to fully monitor for malicious identity access from a centralized location. The added benefits to centralizing all identity data is to facilitate implementation of Single Sign On (SSO) and provide users with a more seamless authentication process, as well as configure Entra ID’s machine learning models to operate on all identity data, thus learning the difference between legitimate access and malicious access quicker and easier. It is recommended to synchronize all user accounts except administrative and high privileged ones when doing this to maintain a boundary between the on-premises environment and the cloud environment, in case of a breach.
• Secure accounts with credential hygiene: practice the principle of least privilege and audit privileged account activity in your Entra ID environments to slow and stop the threat actor.

Microsoft Defender XDR detections

Microsoft Defender XDR customers can refer to the list of applicable detections below. Microsoft Defender XDR coordinates detection, prevention, investigation, and response across endpoints, identities, email, and apps to provide integrated protection against attacks like the threat discussed in this blog.

Customers with provisioned access can also use Microsoft Security Copilot in Microsoft Defender to investigate and respond to incidents, hunt for threats, and protect their organization with relevant threat intelligence.

Using Safe Links and Microsoft Entra ID protection raises high confidence Device Code phishing alerts from Defender.

Microsoft Sentinel

Microsoft Sentinel customers can use the TI Mapping analytics (a series of analytics all prefixed with ‘TI map’) to automatically match the malicious indicators mentioned in this blog post with data in their workspace. Additionally, Microsoft Sentinel customers can use the following queries to detect phishing attempts and email exfiltration attempts via Graph API. These queries can help customers remain vigilant and safeguard their organization from phishing attacks:

• Campaign with suspicious keywords
• Determine Successfully Delivered Phishing Emails to Inbox/Junk folder.
• Successful Sign-in from Phishing Link
• Phishing link click observed in Network Traffic
• Suspicious URL clicked Anomaly of MailItemAccess by GraphAPI
• OAuth Apps accessing user mail via GraphAPI
• OAuth Apps reading mail both via GraphAPI and directly
• OAuth Apps reading mail via GraphAPI anomaly 

Microsoft Security Copilot  

Security Copilot customers can use the standalone experience to create their own prompts or run the following prebuilt promptbooks to automate incident response or investigation tasks related to this threat:  

• Incident investigation  
• Microsoft User analysis  
• Threat actor profile  
• Threat Intelligence 360 report based on MDTI article  
• Vulnerability impact assessment  

Note that some promptbooks require access to plugins for Microsoft products such as Microsoft Defender XDR or Microsoft Sentinel.  

Threat intelligence reports

Microsoft customers can use the following reports in Microsoft products to get the most up-to-date information about the threat actor, malicious activity, and techniques discussed in this blog. These reports provide intelligence, protection information, and recommended actions to prevent, mitigate, or respond to associated threats found in customer environments.

Advanced hunting

Defender XDR customers can run the following queries to identify possible device code phishing related activity in their networks:

Validate errorCode 50199 followed by success in 5-minute time interval for the interested user, which suggests a pause to input the code from the phishing email.

EntraIdSigninEvents
    | where ErrorCode in (0, 50199)
    | summarize ErrorCodes = make_set(ErrorCode) by AccountUpn, CorrelationId, SessionId, bin(Timestamp, 1h)
    | where ErrorCodes has_all (0, 50199)

Validate Device code authentication from suspicious IP Ranges.

EntraIdSigninEvents
    | where Call has “Cmsi:cmsi” 
    | where IPAddress has_any (“160.220.232.”, “160.220.234.”, “89.150.45.”, “185.81.113.”, “8.228.105.”)

Correlate any URL clicks with suspicious sign-ins that follow with user interrupt indicated by the error code 50199.

let suspiciousUserClicks = materialize(UrlClickEvents
    | extend AccountUpn = tolower(AccountUpn)
    | project ClickTime = Timestamp, ActionType, UrlChain, NetworkMessageId, Url, AccountUpn);
//Check for Risky Sign-In in the short time window
let interestedUsersUpn = suspiciousUserClicks
    | where isnotempty(AccountUpn)
    | distinct AccountUpn;
EntraIdSigninEvents
    | where ErrorCode == 0
    | where AccountUpn in~ (interestedUsersUpn)
    | where RiskLevelDuringSignin in (10, 50, 100)
    | extend AccountUpn = tolower(AccountUpn)
    | join kind=inner suspiciousUserClicks on AccountUpn
    | where (Timestamp - ClickTime) between (-2min .. 7min)
    | project Timestamp, ReportId, ClickTime, AccountUpn, RiskLevelDuringSignin, SessionId, IPAddress, Url

Monitor for suspicious Device Registration activities that follow the Device code phishing compromise.

CloudAppEvents
| where AccountDisplayName == "Device Registration Service"
| extend ApplicationId_ = tostring(ActivityObjects[0].ApplicationId)
| extend ServiceName_ = tostring(ActivityObjects[0].Name)
| extend DeviceName = tostring(parse_json(tostring(RawEventData.ModifiedProperties))[1].NewValue)
| extend DeviceId = tostring(parse_json(tostring(parse_json(tostring(RawEventData.ModifiedProperties))[6].NewValue))[0])
| extend DeviceObjectId_ = tostring(parse_json(tostring(RawEventData.ModifiedProperties))[0].NewValue)
| extend UserPrincipalName = tostring(RawEventData.ObjectId)
| project TimeGenerated, ServiceName_, DeviceName, DeviceId, DeviceObjectId_, UserPrincipalName

Surface suspicious inbox rule creation (using applications) that follow the Device code phishing compromise.

CloudAppEvents
| where ApplicationId == “20893” // Microsoft Exchange Online
| where ActionType in ("New-InboxRule","Set-InboxRule","Set-Mailbox","Set-TransportRule","New-TransportRule","Enable-InboxRule","UpdateInboxRules")
| where isnotempty(IPAddress)
| mv-expand ActivityObjects
| extend name = parse_json(ActivityObjects).Name
| extend value = parse_json(ActivityObjects).Value
| where name == "Name"
| extend RuleName = value 
// we are extracting rule names that only contains special characters
| where RuleName matches regex "^[!@#$%^&*()_+={[}\\]|\\\\:;""'<,>.?/~` -]+$"

Surface suspicious email items accessed that follow the Device code phishing compromise.

CloudAppEvents
| where ApplicationId == “20893” // Microsoft Exchange Online
| where ActionType == “MailItemsAccessed”
| where isnotempty(IPAddress)
| where UncommonForUser has "ISP"

Indicators of compromise (IOC)

References

• Storm-2372 conducts device code phishing campaign
• Microsoft Documentation – OAuth 2.0 device authorization grant flow
• Huntress – Riding the Rails: Threat Actors Abuse Railway.com PaaS as Microsoft 365 Token Attack Infrastructure
• Seqoia – New widespread EvilTokens kit: device code phishing as-a-service – Part 1

This research is provided by Microsoft Defender Security Research with contributions from Krithika Ramakrishnan, Ofir Mastor, Bharat Vaghela, Shivas Raina, Parasharan Raghavan, and other members of Microsoft Threat Intelligence.

Learn more

Review our documentation to learn more about our real-time protection capabilities and see how to enable them within your organization.   

• Evaluate your AI readiness with our latest Zero Trust for AI workshop.
• Learn more about Protect your agents in real-time during runtime (Preview)
• Explore how to build and customize agents with Copilot Studio Agent Builder 
• Microsoft 365 Copilot AI security documentation 
• How Microsoft discovers and mitigates evolving attacks against AI guardrails 
• Learn more about securing Copilot Studio agents with Microsoft Defender  

The post Inside an AI‑enabled device code phishing campaign appeared first on Microsoft Security Blog.

However, like defenders, there is typically a human-in-the-loop still powering these attacks, and not fully autonomous or agentic AI running campaigns. AI is reducing friction across the attack lifecycle; helping threat actors research faster, write better lures, vibe code malware, and triage stolen data. The security leaders I spoke with at RSAC™ 2026 Conference this week are prioritizing resources and strategy shifts to get ahead of this critical progression across the threat landscape.

The operational reality: Embedded, not emerging

The scale of what we are tracking makes the scope impossible to dismiss. Threat activity spans every region. The United States alone represents nearly 25% of observed activity, followed by the United Kingdom, Israel, and Germany. That volume reflects economic and geopolitical realities.¹

But the bigger shift is not geographic, it’s operational. Threat actors are embedding AI into how they work across reconnaissance, malware development, and post-compromise operations. Objectives like credential theft, financial gain, and espionage might look familiar, but the precision, persistence, and scale behind them have changed.

Email is still the fastest inroad

Email remains the fastest and cheapest path to initial access. What has changed is the level of refinement that AI enables in crafting the message that gets someone to click.

When AI is embedded into phishing operations, we are seeing click-through rates reach 54%, compared to roughly 12% for more traditional campaigns. That is a 450% increase in effectiveness. That’s not the result of increased volume, but the result of improved precision. AI is helping threat actors localize content and adapt messaging to specific roles, reducing the friction in crafting a lure that converts into access. When you combine that improved effectiveness with infrastructure designed to bypass multifactor authentication (MFA), the result is phishing operations that are more resilient, more targeted, and significantly harder to defend at scale.

A 450% increase in click-through rates changes the risk calculus for every organization. It also signals that AI is not just being used to do more of the same, it is being used to do it better.

Tycoon2FA: What industrial-scale cybercrime looks like

Tycoon2FA is an example of how the actor we track as Storm-1747 shifted toward refinement and resilience. Understanding how it operated teaches us where threats might be headed, and fueled conversations in the briefing rooms at RSAC 2026 this week that focused on ecosystem instead of individual actors.

Tycoon2FA was not a phishing kit, it was a subscription platform that generated tens of millions of phishing emails per month. It was linked to nearly 100,000 compromised organizations since 2023. At its peak, it accounted for roughly 62% of all phishing attempts that Microsoft was blocking every month. This operation specialized in adversary-in-the-middle attacks designed to defeat MFA. It intercepted credentials and session tokens in real time and allowed attackers to authenticate as legitimate users without triggering alerts, even after passwords were reset.

But the technical capability is only part of the story. The bigger shift is structural. Storm-1747 was not operating alone. This was modular cybercrime: one service handled phishing templates, another provided infrastructure, another managed email distribution, another monetized access. It was effectively an assembly line for identity theft. The services were composable, scalable, and available by subscription.

This is the model that has changed the conversations this week: it is not about a single sophisticated actor; it is about an ecosystem that has industrialized access and lowers the barrier to entry for every actor that plugs into it. That is exactly what AI is doing across the broader threat landscape: making the capabilities of sophisticated actors available to everyone.

Disruption: Closing the threat intelligence loop

Our Digital Crimes Unit disrupted Tycoon2FA earlier this month, seizing 330 domains in coordination with Europol and industry partners. But the goal was not simply to take down websites. The goal was to apply pressure to a supply chain. Cybercrime today is about scalable service models that lower the barrier to entry. Identity is the primary target and MFA bypass is now packaged as a feature. Disrupting one service forces the market to adapt. Sustained pressure fragments the ecosystem. By targeting the economic engine behind attacks, we can reshape the risk environment.

Every time we disrupt an attack, it generates signal. The signal feeds intelligence. The intelligence strengthens detection. Detection is what drives response. That is how we turn threat actor actions into durable defenses, and how the work of disruption compounds over time. Microsoft’s ability to observe at scale, act at scale, and share intelligence at scale is the differentiation that matters. It makes a difference because of how we put it into practice.

AI across the full attack lifecycle

When we step back from any single campaign and look for a broader pattern, AI doesn’t show up in just one phase of an attack; it appears across the entire lifecycle. At RSAC 2026 this week, I offered a frame to help defenders prioritize their response:

• In reconnaissance: AI accelerates infrastructure discovery and persona development, compressing the time between target selection and first contact. 

• In resource development: AI generates forged documents, polished social engineering narratives, and supports infrastructure at scale. 

• For initial access: AI refines voice overlays, deepfakes, and message customization using scraped data, producing lures that are increasingly difficult to distinguish from legitimate communications. 

• In persistence and evasion: AI scales fake identities and automates communication that maintains attacker presence while blending with normal activity. 

• In weaponization: AI enables malware development, payload regeneration, and real-time debugging, producing tooling that adapts to the victim environment rather than relying on static signatures. 

• In post-compromise operations: AI adapts tooling to the specific victim environment and, in some cases, automates ransom negotiation itself. 

The objective has not changed: credential theft, financial gain, and espionage. What has changed is the tempo, the iteration speed, and the ability to test and refine at scale. AI is not just accelerating cyberattacks, it’s upgrading them.

What comes next

In my sessions at RSAC 2026 this week, I shared a set of themes that help define the AI-powered shift in the threat landscape.

The first is the agentic threat model. The scenarios we prepare for have changed. The barrier to launching sophisticated attacks has collapsed. What once required the resources of a nation-state or well-organized criminal enterprise is now accessible to a motivated individual with the right tools and the patience to use them. The techniques have not fundamentally changed; the precision, velocity, and volume have.

The second is the software supply chain. Knowing what software and agents you have deployed and being able to account for their behavior is not a compliance exercise. The agent ecosystem will become the most attacked surface in the enterprise. Organizations that cannot answer basic inventory questions about their agent environment will not be able to defend it.

The third is understanding the value of human talent in a security operation using agentic systems to scale. The security analyst as practitioner is giving way to the security analyst as orchestrator. The talent models organizations are hiring against today are already outdated. But technology can help protect humans who may make mistakes. Though it means auditability of agent decisions is a governance requirement today, not eventually. The SOC of the future demands a fundamentally different kind of defender.

The moment to lead with strategic clarity, ranked priorities, and a hardened posture for agentic accountability is now.

If AI is embedded across the attack lifecycle, intelligence and defense must be embedded across the lifecycle too. Microsoft Threat Intelligence will continue to track, publish, and act on what we are observing in real time. The patterns are visible. The intelligence is there.

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us on LinkedIn (Microsoft Security) and X (@MSFTSecurity) for the latest news and updates on cybersecurity.

¹Microsoft Digital Defense Report 2025.

The post Threat actor abuse of AI accelerates from tool to cyberattack surface appeared first on Microsoft Security Blog.

During tax season, threat actors reliably take advantage of the urgency and familiarity of time-sensitive emails, including refund notices, payroll forms, filing reminders, and requests from tax professionals, to trick targets into opening malicious attachments, scanning QR codes, or following multi-step link chains. Every year, there is an observable uptick in tax-themed campaigns as Tax Day (April 15) approaches in the United States, and this year is no different.

In recent months, Microsoft Threat Intelligence identified email campaigns using lures around W-2, tax forms, or similar themes, or posing as government tax agencies, tax services firms, and relevant financial institutions. Many campaigns target individuals for personal and financial data theft, but others specifically target accountants and other professionals who handle sensitive documents, have access to financial data, and are accustomed to receiving tax-related emails during this period.

Identified campaigns were designed to harvest credentials or deliver malware. Phishing-as-a-service (PhaaS) platforms continue to be prevalent, enabling highly convincing credential theft and multifactor authentication (MFA) bypass campaigns through tailored tax-themed social engineering lures, attachments, and phishing pages. In cases of malware delivery, we noted a continued trend of abusing legitimate remote monitoring and management tools (RMMs), which allow threat actors to maintain persistence on a compromised device or network, enable an alternative command-and-control method, or, in the case of hands-on-keyboard attacks, use as an interactive remote desktop session.

This blog details several of the campaigns observed by Microsoft Threat Intelligence in the past few months that leveraged the tax season for social engineering. By educating users about phishing lures, configuring essential email security settings, and defending against credential theft, individuals and organizations can defend against both this seasonal surge in phishing attacks and more broadly against many types of phishing attacks that we observe.

A wide range of tax-themed campaigns

CPA lures leading to Energy365 phishing kit

In early February 2026, we observed a campaign that was delivering the Energy365 PhaaS phishing kit and used tax and Certified Public Accountant (CPA) lures throughout the attack chain. This campaign stood out due to its highly specific lure customization, in contrast to other threat actors who use this popular phishing kit but employ generic lures. Other notable characteristics of this campaign include the involvement of multiple file formats such as Excel and OneNote, use of legitimate infrastructure such as OneDrive, and multiple rounds of user interaction, all attempts to complicate automated and reputation-based detection. While this specific campaign was not large, it represents the capabilities of Energy365, one of the leading phishing kits that enables hundreds of thousands of malicious emails observed by Microsoft daily.

Between February 5 and 6, several hundred emails with the subject ”See Tax file” targeted multiple industries including financial services, education, information technology (IT), insurance, and healthcare, primarily in the United States. The Excel attachment had the file name [Accountant’s name] CPA.xlsx, using the name of a real accountant (likely impersonated in this campaign without their knowledge). The attachment contained a clickable “REVIEW DOCUMENTS” button that linked to a OneNote file hosted on OneDrive.

The OneNote file, which continued the ruse by using the same CPA’s name and logo, contained a link leading to a malicious landing page that hosted the Energy365 phishing kit and attempted to harvest credentials such as email and password.

QR code and W2 lure leading to SneakyLog phishing kit

On February 10, 2026, Microsoft Threat Intelligence observed tax-themed phishing emails sent to approximately 100 organizations, in the manufacturing, retail, and healthcare industries primarily in the United States. The emails used the subject “2025 Employee Tax Docs” and contained an attachment named 2025_Employee_W-2  .docx. The attachment had content that mentioned various tax-related terms like Form W-2 and had a QR code pointing to a phishing page.

Each document was customized to contain the recipient’s name, and the URL hidden behind the QR code also contained the recipient’s email address. This means that each recipient received a unique attachment. The phishing page was built with the SneakyLog PhaaS platform and mimicked the Microsoft 365 sign-in page to steal credentials. SneakyLog, which is also known as Kratos, has been around since at least the beginning of 2025. This phishing kit is sold as a part of phishing-as-a-service and is capable of harvesting credentials and 2FA. While not as popular as other platforms like Energy365, SneakyLog has been consistently present in the threat landscape.

Form 1099-themed phishing delivering ScreenConnect

In January and February 2026, Microsoft Threat Intelligence observed sets of tax-themed domains registered, likely to be used in tax-themed phishing campaigns. These domains used keywords such as “tax” and “1099form” and also impersonated specific legitimate companies involved in tax filing, accounting, investing sectors. Brand abuse of legitimate accounting, tax preparation, finance, bookkeeping, and related companies continues to proliferate during tax season.

We observed one of these domains being used in a campaign between February 8 and February 10. Several hundred emails were sent to recipients in a wide range of industries primarily in the United States. The emails used subject lines like “Your Account Now Includes Updated Tax Forms [RF] 1234” or “Your Form 1099-R is ready – [RF] 12123123”. The email body said “2025 Tax Forms is ready” and contained a clickable “View Tax Forms” button that linked to the URL taxationstatments2025[.]com. If clicked, this domain redirected to tax-statments2025[.]com, which in turn served a malware executable named 1099-FR2025.exe.

The payload delivered in this campaign is the remote management and monitoring (RMM) tool ScreenConnect, signed by ConnectWise. The specific code signing certificate has since been revoked by the issuer due to high abuse. ScreenConnect is a legitimate tool, but threat actors have learned to abuse RMM functionality and essentially turn legitimate tools into remote access trojans (RATs), helping them take control of compromised devices.

IRS and cryptocurrency-themed phishing delivering SimpleHelp

Another notable campaign combined the impersonation of the US Internal Revenue Service (IRS) with a cryptocurrency lure. Notably, this campaign attempted to evade detection by not including a clickable link, but instead asked recipients to copy and paste a URL, which was in the email body, into the browser.

This campaign was sent on February 23 and 27, and it consisted of several thousands of emails sent to recipients exclusively in the United States. The emails targeted many industries, with the bulk of email sent to higher education. The emails used the subject “IR-2026-216” and abused online platform Eventbrite to masquerade as coming from the IRS:

• “IRS US”<noreply@campaign[.]eventbrite[.]com>
• “IRS GOV”<noreply@campaign[.]eventbrite[.]com>
• “Service”<noreply@campaign[.]eventbrite[.]com>
• “IRS TAX”<noreply@campaign[.]eventbrite[.]com>
• “.IRS.GOV”<noreply@campaign[.]eventbrite[.]com>

The email body said “Cryptocurrency Tax Form 1099 is Ready” and contained a non-clickable URL with the domain irs-doc[.]com or gov-irs216[.]net. If pasted in the browser, the URL led to the download of IRS-doc.msi, which was either the RMM tool ScreenConnect or SimpleHelp, depending on the day of the campaign. SimpleHelp is another legitimate remote monitoring and management tool abused by threat actors. While not as popular as ScreenConnect, threat actors have been increasingly adopting SimpleHelp due to the recent crackdown on abuse of ScreenConnect by ConnectWise.

Campaign targeting CPAs and delivering Datto

Like in previous tax seasons, Microsoft Threat Intelligence observed email campaigns specifically targeting accountants and related organizations. A variant of this campaign is a well-known and documented technique that uses benign conversation starters. The threat actor reaches out asking for assistance in filing taxes, asking for a quote, and typically providing a backstory. If the actor receives a reply, they send a malicious link that leads to the installation of various RATs. However, Microsoft Threat Intelligence also observed campaigns targeting CPAs that contain a similar backstory but include the malicious link in the first email.

One such campaign was sent on March 9 and consisted of approximately 1,000 emails sent to users exclusively in the United States. The emails targeted multiple accounting companies but also included a few related industries such as financial services, legal, and insurance. The emails used the subject “REQUEST FOR PROFESSIONAL TAX FILLING”.

The email provided a backstory that included a description of a complex tax return situation involving tax audit, university tuition, loan interest, and real estate income. The sender also attempted to explain their inability to physically visit the office due to travel. Finally, the sender asked for a price quote. We observed variations of the backstory on different days, including switching CPAs due to fee increases.

The link in email used the free site hosting service carrd[.]co. The site contained a simple “VIEW DOCUMENTS” button that linked to a URL shortener service, which redirected users to private-adobe-client[.]im. This uncomplicated redirection chain served to hinder automated detection by using legitimate sites with good reputation and involving user interaction. The final landing page served an executable related to the Datto. Datto is yet another legitimate remote monitoring and management tool, abused by threat actors.

IRS-themed campaign targeting accounting professionals and dropping ScreenConnect

On February 10, 2026, Microsoft Threat Intelligence observed a large-scale phishing campaign sent to more than 29,000 users across 10,000 organizations, almost exclusively focused on targets in the United States (95% of targets). The campaign did not concentrate on any single sector but instead included a wide set of industries, with financial services (19%), technology and software (18%), and retail and consumer goods (15%) being the most commonly targeted.

While the campaign did not seem to have been targeting a specific industry, an analysis of intended recipients indicated that the campaign was targeting specific roles, particularly accountants and tax preparers. Messages in the campaign were sent in two waves over a nine‑hour window between 10:35 UTC and 19:51 UTC.  

The emails impersonated the IRS, claiming that potentially irregular tax returns had been filed under the recipient’s Electronic Filing Identification Number (EFIN). Recipients were instructed to review these returns by downloading a purportedly legitimate “IRS Transcript Viewer.”

The emails were sent through Amazon Simple Email Service (SES) from one of two sender addresses on edud[.]site, a domain registered in August 2025. To enhance credibility, the sender display name rotated among the following 14 IRS‑themed identities:

• IRS e-File Services
• IRS EFIN Team
• IRS EFIN Compliance
• IRS e-Services
• IRS E-File Operations
• IRS Filing Review
• IRS Filing Support
• IRS EFIN Support
• IRS e-Services Team
• IRS e-File Support
• IRS EFIN Review
• IRS e-File Compliance
• IRS e-Services Support
• IRS Practitioner e-Services

Similarly, the subject lines used in the campaign also rotated, presumably to try and circumvent detection systems that rely on static text signatures. The most common among the 49 email subjects we observed in this campaign include:

• IRS Request Transcript Review
• IRS Notice Firm Return Review
• CPA Compliance Review
• IRS Support Firm Filing Review
• Review Requested Compliance

The emails contained a “Download IRS Transcript View 5.1” button, which purported to lead to a legitimate IRS application that could be used to review the transcript referenced in the email. Instead, the link pointed to an Amazon SES click‑tracking URL (awstrack[.]me), which then redirected to smartvault[.]im, a malicious look‑alike domain mimicking SmartVault, a well‑known tax and document‑management service used by accounting professionals. To evade automated analysis, the phishing site used Cloudflare for bot detection and blocking. Only visitors who resembled human users would be able to reach the final phishing payload, while traffic from crawlers and sandboxes would result in a block page.

Users who passed the bot check would be shown a fake “verification” animation that indicated the IRS website was conducting an automated check to verify the connection with IRS provider services. After this animation, a user would be shown a page indicating that the supposed transcript viewer application would start downloading automatically before being redirected to the legitimate IRS provider services webpage. The downloaded file, named TranscriptViewer5.1.exe, was not a legitimate IRS tool but a maliciously repackaged ScreenConnect remote access tool (RAT). Upon execution, this payload could grant attackers remote control of the victim system, enabling data theft, credential harvesting, and further post‑exploitation activity.

How to protect users and organization against tax-themed campaigns

To defend against social engineering campaigns that leverage the surge in email activity during Tax Season, Microsoft recommends the following mitigation measures:

• Configure automatic attack disruption in Microsoft Defender XDR. Automatic attack disruption is designed to contain attacks in progress, limit the impact on an organization’s assets, and provide more time for security teams to remediate the attack fully.
• Enforce multifactor authentication (MFA) on all accounts, remove users excluded from MFA, and strictly require MFA from all devices in all locations at all times.
• Use the Microsoft Authenticator app for passkeys and MFA, and complement MFA with conditional access policies, where sign-in requests are evaluated using additional identity-driven signals.
• Conditional access policies can also be scoped to strengthen privileged accounts with phishing resistant MFA.
• Enable Zero-hour auto purge (ZAP) in Office 365 to quarantine sent mail in response to newly acquired threat intelligence and retroactively neutralize malicious phishing, spam, or malware messages that have already been delivered to mailboxes.
• Configure Microsoft Defender for Office 365 Safe Links to recheck links on click. Safe Links provides URL scanning and rewriting of inbound email messages in mail flow and time-of-click verification of URLs and links in email messages, other Microsoft Office applications such as Teams, and other locations such as SharePoint Online. Safe Links scanning occurs in addition to the regular anti-spam and anti-malware protection in inbound email messages in Microsoft Exchange Online Protection (EOP). Safe Links scanning can help protect your organization from malicious links that are used in phishing and other attacks.
• Invest in advanced anti-phishing solutions that monitor and scan incoming emails and visited websites. For example, organizations can leverage web browsers like Microsoft Edge that automatically identify and block malicious websites, including those used in this phishing campaign, and solutions that detect and block malicious emails, links, and files.
• Encourage users to use Microsoft Edge and other web browsers that support Microsoft Defender SmartScreen, which identifies and blocks malicious websites, including phishing sites, scam sites, and sites that host malware.
• Enable network protection to prevent applications or users from accessing malicious domains and other malicious content on the internet.

Microsoft Defender detection and hunting guidance

Microsoft Defender customers can refer to the list of applicable detections below. Microsoft Defender XDR coordinates detection, prevention, investigation, and response across endpoints, identities, email, apps to provide integrated protection against attacks like the threat discussed in this blog.

Microsoft Security Copilot

Microsoft Security Copilot is embedded in Microsoft Defender and provides security teams with AI-powered capabilities to summarize incidents, analyze files and scripts, summarize identities, use guided responses, and generate device summaries, hunting queries, and incident reports.

Customers can also deploy AI agents, including the following Microsoft Security Copilot agents, to perform security tasks efficiently:

• Threat Intelligence Briefing agent
• Phishing Triage agent
• Threat Hunting agent
• Dynamic Threat Detection agent

Security Copilot is also available as a standalone experience where customers can perform specific security-related tasks, such as incident investigation, user analysis, and vulnerability impact assessment. In addition, Security Copilot offers developer scenarios that allow customers to build, test, publish, and integrate AI agents and plugins to meet unique security needs.

Threat intelligence reports

Microsoft Defender XDR customers can use the following threat analytics reports in the Defender portal (requires license for at least one Defender XDR product) to get the most up-to-date information about the threat actor, malicious activity, and techniques discussed in this blog. These reports provide the intelligence, protection information, and recommended actions to prevent, mitigate, or respond to associated threats found in customer environments:

• Threat Overview Profile: On-premises credential theft
• Technique Profile: Abuse of remote monitoring and management tools

Microsoft Security Copilot customers can also use the Microsoft Security Copilot integration in Microsoft Defender Threat Intelligence, either in the Security Copilot standalone portal or in the embedded experience in the Microsoft Defender portal to get more information about this threat actor.

Hunting queries

Microsoft Defender XDR

Microsoft Defender XDR customers can run the following advanced hunting queries to find related activity in their networks:

Find email messages related to known domains

The following query checks domains in Defender XDR email data:

EmailUrlInfo  
| where UrlDomain has_any ("taxationstatments2025.com", "irs-doc.com", "gov-irs216.net", "private-adobe-client.im", "edud.site", "smartvault.im")

Detect file hash indicators in email data

The following query checks hashes related to identified phishing activity in Defender XDR data:

let File_Hashes_SHA256 = dynamic([
"45b6b4db1be6698c29ffde9daeb8ffaa344b687d3badded2f8c68c922cdce6e0", "d422f6f5310af1e72f6113a2a592916f58e3871c58d0e46f058d4b669a3a0fd8"]);
DeviceFileEvents
| where SHA256 has_any (File_Hashes_SHA256)

Microsoft Sentinel

Microsoft Sentinel customers can use the TI Mapping analytics (a series of analytics all prefixed with ‘TI map’) to automatically match the indicators mentioned in this blog post with data in their workspace. If the TI Map analytics are not currently deployed, customers can install the Threat Intelligence solution from the Microsoft Sentinel Content Hub to have the analytics rule deployed in their Sentinel workspace.

The following queries use Sentinel Advanced Security Information Model (ASIM) functions to hunt threats across both Microsoft first-party and third-party data sources. ASIM also supports deploying parsers to specific workspaces from GitHub, using an ARM template or manually.

Detect network IP and domain indicators of compromise using ASIM

The following query checks IP addresses and domain IOCs across data sources supported by ASIM network session parser:

//IP list and domain list- _Im_NetworkSession
let lookback = 30d;
let ioc_ip_addr = dynamic([]);
let ioc_domains = dynamic(["taxationstatments2025.com", "irs-doc.com", "gov-irs216.net", "private-adobe-client.im"]);
_Im_NetworkSession(starttime=todatetime(ago(lookback)), endtime=now())
| where DstIpAddr in (ioc_ip_addr) or DstDomain has_any (ioc_domains)
| summarize imNWS_mintime=min(TimeGenerated), imNWS_maxtime=max(TimeGenerated),
  EventCount=count() by SrcIpAddr, DstIpAddr, DstDomain, Dvc, EventProduct, EventVendor

Detect Web Sessions IP and file hash indicators of compromise using ASIM

The following query checks IP addresses, domains, and file hash IOCs across data sources supported by ASIM web session parser:

//IP list - _Im_WebSession
let lookback = 30d;
let ioc_ip_addr = dynamic([]);
let ioc_sha_hashes =dynamic(["45b6b4db1be6698c29ffde9daeb8ffaa344b687d3badded2f8c68c922cdce6e0"]);
_Im_WebSession(starttime=todatetime(ago(lookback)), endtime=now())
| where DstIpAddr in (ioc_ip_addr) or FileSHA256 in (ioc_sha_hashes)
| summarize imWS_mintime=min(TimeGenerated), imWS_maxtime=max(TimeGenerated),
  EventCount=count() by SrcIpAddr, DstIpAddr, Url, Dvc, EventProduct, EventVendor

Detect domain and URL indicators of compromise using ASIM

The following query checks domain and URL IOCs across data sources supported by ASIM web session parser:

// file hash list - imFileEvent
// Domain list - _Im_WebSession
let ioc_domains = dynamic(["taxationstatments2025.com", "irs-doc.com", "gov-irs216.net", "private-adobe-client.im"]);
_Im_WebSession (url_has_any = ioc_domains)

Detect files hashes indicators of compromise using ASIM

The following query checks IP addresses and file hash IOCs across data sources supported by ASIM file event parser:

// file hash list - imFileEvent
let ioc_sha_hashes = dynamic(["45b6b4db1be6698c29ffde9daeb8ffaa344b687d3badded2f8c68c922cdce6e0"]);
imFileEvent
| where SrcFileSHA256 in (ioc_sha_hashes) or
TargetFileSHA256 in (ioc_sha_hashes)
| extend AccountName = tostring(split(User, @'')[1]), 
  AccountNTDomain = tostring(split(User, @'')[0])
| extend AlgorithmType = "SHA256"

Indicators of compromise

Learn more

For the latest security research from the Microsoft Threat Intelligence community, check out the Microsoft Threat Intelligence Blog.

To get notified about new publications and to join discussions on social media, follow us on LinkedIn, X (formerly Twitter), and Bluesky.

To hear stories and insights from the Microsoft Threat Intelligence community about the ever-evolving threat landscape, listen to the Microsoft Threuat Intelligence podcast.

The post When tax season becomes cyberattack season: Phishing and malware campaigns using tax-related lures appeared first on Microsoft Security Blog.

This case highlights a growing class of cyberattacks that exploit trust, collaboration platforms, and built-in tooling, and underscores why defenders must be prepared to detect and disrupt these techniques before they escalate. Read the full report to dive deeper into this vishing breach of trust.

What happened?

Once remote interactive access was established, the threat actor shifted from social engineering to hands-on keyboard compromise, steering the user toward a malicious website under their control. Evidence gathered from browser history and Quick Assist artifacts showed the user was prompted to enter corporate credentials into a spoofed web form, which then initiated the download of multiple malicious payloads. One of the earliest artifacts—a disguised Microsoft Installer (MSI) package—used trusted Windows mechanisms to sideload a malicious dynamic link library (DLL) and establish outbound command-and-control, allowing the threat actor to execute code under the guise of legitimate software.

Subsequent payloads expanded this foothold, introducing encrypted loaders, remote command execution through standard administrative tooling, and proxy-based connectivity to obscure threat actor activity. Over time, additional components enabled credential harvesting and session hijacking, giving the threat actor sustained, interactive control within the environment and the ability to operate using techniques designed to blend in with normal enterprise activity rather than trigger overt alarms.

How did Microsoft respond?

Given the growing pattern of identity-first intrusions that begin with collaboration-based social engineering, DART moved quickly to contain risk and validate scope. The team confirmed that the compromise originated from a successful Microsoft Teams voice phishing interaction and immediately prioritized actions to prevent identity or directory-level impact. Through focused investigation, we established that the activity was short-lived and limited in reach, allowing responders to concentrate on early-stage tooling and entry points to understand how access was achieved and constrained.

To disrupt the intrusion, DART conducted targeted eviction and applied tactical containment controls to protect privileged assets and restrict lateral movement. Using proprietary forensic and investigation tooling, the team collected and analyzed evidence across affected systems, validated that threat actor objectives were not met, and confirmed the absence of persistence mechanisms. These actions enabled rapid recovery while helping to ensure the environment was fully secured before declaring the incident resolved.

What can customers do to strengthen their defenses?

Human nature works against us in these cyberattacks. Employees are conditioned to be responsive, helpful, and collaborative, especially when requests appear to come from internal IT or support teams. Threat actors exploit that instinct, using voice phishing and collaboration tools to create a sense of urgency and legitimacy that can override caution in the moment.

To mitigate exposure, DART recommends organizations take deliberate steps to limit how social engineering attacks can propagate through Microsoft Teams and how legitimate remote access tools can be misused. This starts with tightening external collaboration by restricting inbound communications from unmanaged Teams accounts and implementing an allowlist model that permits contact only from trusted external domains. At the same time, organizations should review their use of remote monitoring and management tools, inventory what is truly required, and remove or disable utilities—such as Quick Assist—where they are unnecessary.

Together, these measures help shrink the attack surface, reduce opportunities for identity-driven compromise, and make it harder for threat actors to turn human trust into initial access, while preserving the collaboration employees rely on to do their work.

What is the Cyberattack Series?

In our Cyberattack Series, customers discover how DART investigates unique and notable attacks. For each cyberattack story, we share:

• How the cyberattack happened.
• How the breach was discovered.
• Microsoft’s investigation and eviction of the threat actor.
• Strategies to avoid similar cyberattacks.

DART is made up of highly skilled investigators, researchers, engineers, and analysts who specialize in handling global security incidents. We’re here for customers with dedicated experts to work with you before, during, and after a cybersecurity incident.

Learn more

To learn more about DART capabilities, please visit our website, or reach out to your Microsoft account manager or Premier Support contact. To learn more about the cybersecurity incidents described above, including more insights and information on how to protect your own organization, download the full report.

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us on LinkedIn (Microsoft Security) and X (@MSFTSecurity) for the latest news and updates on cybersecurity.

¹Microsoft Digital Defense Report 2025.

The post Help on the line: How a Microsoft Teams support call led to compromise appeared first on Microsoft Security Blog.

Following its emergence in August 2023, Tycoon2FA rapidly became one of the most widespread phishing-as-a-service (PhaaS) platforms, enabling campaigns responsible for tens of millions of phishing messages reaching over 500,000 organizations each month worldwide. The phishing kit—developed, supported, and advertised by the threat actor tracked by Microsoft Threat Intelligence as Storm-1747—provided adversary-in-the-middle (AiTM) capabilities that allowed even less skilled threat actors to bypass multifactor authentication (MFA), significantly lowering the barrier to conducting account compromise at scale.

Tycoon2FA’s platform enabled threat actors to impersonate trusted brands by mimicking sign-in pages for services like Microsoft 365, OneDrive, Outlook, SharePoint, and Gmail. It also allowed threat actors using its service to establish persistence and to access sensitive information even after passwords are reset, unless active sessions and tokens were explicitly revoked. This worked by intercepting session cookies generated during the authentication process, simultaneously capturing user credentials. The MFA codes were subsequently relayed through Tycoon2FA’s proxy servers to the authenticating service.

To evade detection, Tycoon2FA used techniques like anti-bot screening, browser fingerprinting, heavy code obfuscation, self-hosted CAPTCHAs, custom JavaScript, and dynamic decoy pages. Targets are often lured through phishing emails containing attachments like .svg, .pdf, .html, or .docx files, often embedded with QR codes or JavaScript.

This blog provides a comprehensive up-to-date analysis of Tycoon2FA’s progression and scale. We share specific examples of the Tycoon2FA service panel, including a detailed analysis of Tycoon2FA infrastructure. Defending against Tycoon2FA and similar AiTM phishing threats requires a layered approach that blends technical controls with user awareness. This blog also provides Microsoft Defender detection and hunting guidance, as well as resources on how to set up mail flow rules, enforce spoof protections, and configure third-party connectors to prevent spoofed phishing messages from reaching user inboxes.

Operational overview of Tycoon2FA

Tycoon2FA customer panel

Tycoon2FA phishing services were advertised and sold to cybercriminals on applications like Telegram and Signal. Phish kits were observed to start at $120 USD for access to the panel for 10 days and $350 for access to the panel for a month, but these prices could vary.

Tycoon2FA is operated through a web‑based administration panel provided on a per user basis that centrally integrates all functionality provided by the Tycoon 2FA PhaaS platform. The panel serves as a single dashboard for configuring, tracking, and refining campaigns. While it does not include built‑in mailer capabilities, the panel provides the core components needed to support phishing campaigns. This includes pre‑built templates, attachment files for common lure formats, domain and hosting configuration, redirect logic, and victim tracking. This design makes the platform accessible to less technically skilled actors while still offering sufficient flexibility for more experienced operators.

After signing in, Tycoon2FA customers are presented with a dashboard used to configure, monitor, and manage phishing campaigns. Campaign operators can configure a broad set of campaign parameters that control how phishing content is delivered and presented to targets. Key settings include lure template selection and branding customization, redirection routing, MFA interception behavior, CAPTCHA appearance and logic, attachment generation, and exfiltration configuration. Campaign operators can choose from highly configurable landing pages and sign-in themes that impersonate widely trusted services such as Microsoft 365, Outlook, SharePoint, OneDrive, and Google, increasing the perceived legitimacy of attacks.

Campaign operators can also configure how the malicious content is delivered through attachments. Options include generating EML files, PDFs, and QR codes, offering multiple ways to package and distribute phishing lures.

The panel also allows operators to manage redirect chains and routing logic, including the use of intermediate pages and decoy destinations. Support for automated subdomain rotation and intermediary Cloudflare Workers-based URLs enables campaigns to adapt quickly as infrastructure is identified or blocked. The following is a visual example of redirect and routing options, including intermediate pages and decoy destinations used within a phishing campaign.

Once configured, these settings control the appearance and behavior of the phishing pages delivered to targets. The following examples show how selected themes (Microsoft 365 and Outlook) are rendered as legitimate-looking sign-in pages presented to targets.

Beyond campaign configuration, the panel provides detailed visibility into victim interaction and authentication outcomes. Operators can track valid and invalid sign-in attempts, MFA usage, and session cookie capture, with victim data organized by attributes such as targeted service, browser, location, and authentication status. Captured credentials and session cookies can be viewed or downloaded directly within the panel and/or forwarded to Telegram for near‑real‑time monitoring. The following image shows a summary view of victim account outcomes for threat actors to review and track.

Captured session information including account attributes, browsers and location metadata, and authentication artifacts are exfiltrated through Telegram bot.

In addition to configuration and campaign management features, the panel includes a section for announcements and updates related to the service. These updates reflect regular maintenance and ongoing changes, indicating that the service continues to evolve.

By combining centralized configuration, real-time visibility, and regular platform updates, the service enables scalable AiTM phishing operations that can adapt quickly to defensive measures. This balance of usability, adaptability, and sustained development has contributed to Tycoon2FA’s adoption across a wide range of campaigns.

Tycoon2FA infrastructure

Tycoon2FA’s infrastructure has shifted from static, high-entropy domains to a fast-moving ecosystem with diverse top-level domains (TLDs) and short-lived (often 24-72 hours) fully qualified domain names (FQDNs), with the majority hosted on Cloudflare. A key change is the move toward a broader mix of TLDs. Early tracking showed heavier use of regional TLDs like .es and .ru, but recent campaigns increasingly rotated across inexpensive generic TLDs that require little to no identity verification. Examples include .space, .email, .solutions, .live, .today, and .calendar, as well as second-level domains such as .sa[.]com, .in[.]net, and .com[.]de.

Tycoon2FA generated large numbers of subdomains for individual phishing campaigns, used them briefly, then dropped them and spun up new ones. Parent root domains might remain registered for weeks or months, but nearly all campaign-specific FQDNs were temporary. The rapid turnover complicated detection efforts, such as building reliable blocklists or relying on reputation-based defenses.

Subdomain patterns have also shifted toward more readable formats. Instead of high entropy or algorithmically generated strings, like those used in July 2025, newly observed subdomains used recognizable words tied to common workflows or services, like those observed in December 2025.

July 2025 campaign URL structure examples:

• hxxps://qonnfp.wnrathttb[.]ru/Fe2yiyoKvg3YTfV!/$EMAIL_ADDRESS
• hxxps://piwf.ariitdc[.]es/kv2gVMHLZ@dNeXt/$EMAIL_ADDRESS
• hxxps://q9y3.efwzxgd[.]es/MEaap8nZG5A@c8T/*EMAIL_ADDRESS
• hxxps://kzagniw[.]es/LI6vGlx7@1wPztdy

December 2025 campaign URL structure examples:

• hxxps://immutable.nathacha[.]digital/T@uWhi6jqZQH7/#?EMAIL_ADDRESS
• hxxps://mock.zuyistoo[.]today/pry1r75TisN5S@8yDDQI/$EMAIL_ADDRESS
• hxxps://astro.thorousha[.]ru/vojd4e50fw4o!g/$ENCODED EMAIL_ADDRESS
• hxxps://branch.cricomai[.]sa[.]com/b@GrBOPttIrJA/*EMAIL_ADDRESS
• hxxps://mysql.vecedoo[.]online/JB5ow79@fKst02/#EMAIL_ADDRESS
• hxxps://backend.vmfuiojitnlb[.]es/CGyP9!CbhSU22YT2/

Some subdomains resembled everyday processes or tech terms like cloud, desktop, application, and survey, while others echoed developer or admin vocabulary like python, terminal, xml, and faq. Software as a service (SaaS) brand names have appeared in subdomains as well, such as docker, zendesk, azure, microsoft, sharepoint, onedrive, and nordvpn. This shift was likely used to reduce user suspicion and to evade detection models that rely on entropy or string irregularity.

Tycoon2FA’s success stemmed from closely mimicking legitimate authentication processes while covertly intercepting both user credentials and session tokens, granting attackers full access to targeted accounts. Tycoon2FA operators could bypass nearly all commonly deployed MFA methods, including SMS codes, one-time passcodes, and push notifications. The attack chain was typical yet highly effective and started with phishing the user through email, followed by a multilayer redirect chain, then a spoofed sign-in page with AiTM relay, and authentication relay culminating in token theft.

Tycoon2FA phishing emails

In observed campaigns, threat actors gained initial access through phishing emails that used either embedded links or malicious attachments. Most of Tycoon2FA’s lures fell into four categories:

• PDF or DOC/DOCX attachments with QR codes
• SVG files containing embedded redirect logic
• HTML attachments with short messages
• Redirect links that appear to come from trusted services

Email lures were crafted from ready-made templates that impersonated trusted business applications like Microsoft 365, Azure, Okta, OneDrive, Docusign, and SharePoint. These templates spanned themes from generic notifications (like voicemail and shared document access) to targeted workflows (like human resources (HR) updates, corporate documents, and financial statements). In addition to spoofing trusted brands, phishing emails often leveraged compromised accounts with existing threads to increase legitimacy.

While Tycoon2FA supplied hosting infrastructures, along with various phishing and landing page related templates, email distribution was not provided by the service.

Defense evasion

From a defense standpoint, Tycoon2FA stood out for its continuously updated evasion and attack techniques. A defining feature was the use of constantly changing custom CAPTCHA pages that regenerated frequently and varied across campaigns. As a result, static signatures and narrowly scoped detection logic became less effective over time. Before credentials were entered, targets encounter the custom CAPTCHA challenge, which was designed to block automated scanners and ensure real users reach the phishing content. These challenges often used randomized HTML5 canvas elements, making them hard to bypass with automation. While Cloudflare Turnstile was once the primary CAPTCHA, Tycoon2FA shifted to using a rotating set of custom CAPTCHA challenges. The CAPTCHA acted as a gate in the flow, legitimizing the process and nudging the target to continue.

After the CAPTCHA challenge, the user was shown a dynamically generated sign-in portal that mirrored the targeted service’s branding and authentication flow, most often Microsoft or Gmail. The page might even include company branding to enhance legitimacy. When the user submitted credentials, Tycoon2FA immediately relayed them to the real service, triggering the genuine MFA challenge. The phishing page then displayed the same MFA prompt (for example, number matching or code entry). Once the user completed MFA, the attacker captured the session cookie and gained real-time access without needing further authentication, even if the password was changed later. These pages were created with heavily obfuscated and randomized JavaScript and HTML, designed to evade signature-based detection and other security tools.

The phishing kit also disrupted analysis through obfuscation and dynamic code generation, including nonfunctional dead code, to defeat consistent fingerprinting. When the campaign infrastructure encountered an unexpected or invalid server response (for example, a geolocation outside the allowed targeting zone), the kit replaced phishing content with a decoy page or a benign redirect to avoid exposing the live credential phishing site.

Tycoon2FA further complicated investigation by actively checking for analysis of environments or browser automation and adjusting page behavior if detected. These evasive measures included:

• Intercepting user input
  • Keystroke monitoring
  • Blocking copy/paste and right click functions
• Detecting or blocking automated inspection
  • Automation tools (for example, PhantomJS, Burp Suite)
  • Disabling common developer tool shortcuts
• Validating and filtering incoming traffic
  • Browser fingerprinting
  • Datacenter IP filtering
  • Geolocation restrictions
  • Suspicious user agent profiling
• Increased obfuscation
  • Encoded content (Base64, Base91)
  • Fragmented or concatenated strings
  • Invisible Unicode characters
  • Layered URL/URI encoding
  • Dead or nonfunctional script

If analysis was suspected at any point, the kit redirected to a legitimate decoy site or threw a 404 error.

Complementing these anti-analysis measures, Tycoon2FA used increasingly complex redirect logic. Instead of sending victims directly to the phishing page, it chained multiple intermediate hosts, such as Azure Blob Storage, Firebase, Wix, TikTok, or Google resources, to lend legitimacy to the redirect path. Recent changes combined these redirect chains with encoded Uniform Resource Identifier (URI) strings that obscured full URL paths and landing points, frustrating both static URL extraction and detonation attempts. Stacked together, these tactics made Tycoon2FA a resilient, fast-moving system that evaded both automated and manual detection efforts.

Credential theft and account access

Captured credentials and session tokens were exfiltrated over encrypted channels, often via Telegram bots. Attackers could then access sensitive data and establish persistence by modifying mailbox rules, registering new authenticator apps, or launching follow-on phishing campaigns from compromised accounts. The following diagram breaks down the AiTM process.

Tycoon2FA illustrated the evolution of phishing kits in response to rising enterprise defenses, adapting its lures, infrastructure, and evasion techniques to stay ahead of detection. As organizations increasingly adopt MFA, attackers are shifting to tools that target the authentication process itself instead of attempting to circumvent it. Coupled with affordability, scalability, and ease of use, Tycoon2FA posed a persistent and significant threat to both consumer and enterprise accounts, especially those that rely on MFA as a primary safeguard.

Mitigation and protection guidance

Mitigating threats from phishing actors begins with securing user identity by eliminating traditional credentials and adopting passwordless, phishing-resistant MFA methods such as FIDO2 security keys, Windows Hello for Business, and Microsoft Authenticator passkeys.

Microsoft Threat Intelligence recommends enforcing phishing-resistant MFA for privileged roles in Microsoft Entra ID to significantly reduce the risk of account compromise. Learn how to require phishing-resistant MFA for admin roles and plan a passwordless deployment.

Passwordless authentication improves security as well as enhances user experience and reduces IT overhead. Explore Microsoft’s overview of passwordless authentication and authentication strength guidance to understand how to align your organization’s policies with best practices. For broader strategies on defending against identity-based attacks, refer to Microsoft’s blog on evolving identity attack techniques.

If Microsoft Defender alerts indicate suspicious activity or confirmed compromised account or a system, it’s essential to act quickly and thoroughly. The following are recommended remediation steps for each affected identity:

1. Reset credentials – Immediately reset the account’s password and revoke any active sessions or tokens. This ensures that any stolen credentials can no longer be used.
2. Re-register or remove MFA devices – Review users’ MFA devices, specifically those recently added or updated.
3. Revert unauthorized payroll or financial changes – If the attacker modified payroll or financial configurations, such as direct deposit details, revert them to their original state and notify the appropriate internal teams.
4. Remove malicious inbox rules – Attackers often create inbox rules to hide their activity or forward sensitive data. Review and delete any suspicious or unauthorized rules.
5. Verify MFA reconfiguration – Confirm that the user has successfully reconfigured MFA and that the new setup uses secure, phishing-resistant methods.

To defend against the wide range of phishing threats, Microsoft Threat Intelligence recommends the following mitigation steps:

• Review our recommended settings for Exchange Online Protection and Microsoft Defender for Office 365.
• Configure Microsoft Defender for Office 365 to recheck links on click. Safe Links provides URL scanning and rewriting of inbound email messages in mail flow, and time-of-click verification of URLs and links in email messages, other Microsoft 365 applications such as Teams, and other locations such as SharePoint Online. Safe Links scanning occurs in addition to the regular anti-spam and anti-malware protection in inbound email messages in Microsoft Exchange Online Protection (EOP). Safe Links scanning can help protect your organization from malicious links used in phishing and other attacks.
• Turn on Zero-hour auto purge (ZAP) in Defender for Office 365 to quarantine sent mail in response to newly-acquired threat intelligence and retroactively neutralize malicious phishing, spam, or malware messages that have already been delivered to mailboxes.
• Turn on Safe Links and Safe Attachments in Microsoft Defender for Office 365.
• Enable network protection in Microsoft Defender for Endpoint.
• Encourage users to use Microsoft Edge and other web browsers that support Microsoft Defender SmartScreen, which identifies and blocks malicious websites, including phishing sites, scam sites, and sites that host malware.
• Turn on cloud-delivered protection in Microsoft Defender Antivirus or the equivalent for your antivirus product to cover rapidly evolving attack tools and techniques. Cloud-based machine learning protections block a majority of new and unknown variants
• Use the Attack Simulator in Microsoft Defender for Office 365 to run realistic, yet safe, simulated phishing and password attack campaigns. Run spear-phishing (credential harvest) simulations to train end-users against clicking URLs in unsolicited messages and disclosing credentials.
• Configure automatic attack disruption in Microsoft Defender XDR. Automatic attack disruption is designed to contain attacks in progress, limit the impact on an organization’s assets, and provide more time for security teams to remediate the attack fully.
• Configure Microsoft Entra with increased security.
• Pilot and deploy phishing-resistant authentication methods for users.
• Implement Entra ID Conditional Access authentication strength to require phishing-resistant authentication for employees and external users for critical apps.

Microsoft Defender detections

Microsoft Defender customers can refer to the list of applicable detections below. Microsoft Defender coordinates detection, prevention, investigation, and response across endpoints, identities, email, apps to provide integrated protection against attacks like the threat discussed in this blog.

Customers with provisioned access can also use Microsoft Security Copilot in Microsoft Defender to investigate and respond to incidents, hunt for threats, and protect their organization with relevant threat intelligence.

The following alerts might indicate threat activity associated with this threat. These alerts, however, can be triggered by unrelated threat activity and are not monitored in the status cards provided with this report.

Additionally, using Microsoft Defender for Cloud Apps connectors, Microsoft Defender XDR raises AiTM-related alerts in multiple scenarios. For Microsoft Entra ID customers using Microsoft Edge, attempts by attackers to replay session cookies to access cloud applications are detected by Microsoft Defender XDR through Defender for Cloud Apps connectors for Microsoft Office 365 and Azure. In such scenarios, Microsoft Defender XDR raises the following alerts:

• Stolen session cookie was used
• User compromised through session cookie hijack

Microsoft Defender XDR raises the following alerts by combining Microsoft Defender for Office 365 URL click and Microsoft Entra ID Protection risky sign-ins signal.

• Possible AiTM phishing attempt
• Risky sign-in attempt after clicking a possible AiTM phishing URL

Microsoft Security Copilot

Microsoft Security Copilot is embedded in Microsoft Defender and provides security teams with AI-powered capabilities to summarize incidents, analyze files and scripts, summarize identities, use guided responses, and generate device summaries, hunting queries, and incident reports.

Customers can also deploy AI agents, including the following Microsoft Security Copilot agents, to perform security tasks efficiently:

• Threat Intelligence Briefing agent
• Phishing Triage agent
• Threat Hunting agent
• Dynamic Threat Detection agent

Security Copilot is also available as a standalone experience where customers can perform specific security-related tasks, such as incident investigation, user analysis, and vulnerability impact assessment. In addition, Security Copilot offers developer scenarios that allow customers to build, test, publish, and integrate AI agents and plugins to meet unique security needs.

Threat intelligence reports

Microsoft Defender XDR customers can use the following threat analytics reports in the Defender portal (requires license for at least one Defender XDR product) to get the most up-to-date information about the threat actor, malicious activity, and techniques discussed in this blog. These reports provide intelligence, protection information, and recommended actions to prevent, mitigate, or respond to associated threats found in customer environments:

• Actor profile: Storm-1747
• Tool profile: Tycoon2FA
• Technique profile: Adversary-in-the-middle credential phishing

Microsoft Security Copilot customers can also use the Microsoft Security Copilot integration in Microsoft Defender Threat Intelligence, either in the Security Copilot standalone portal or in the embedded experience in the Microsoft Defender portal to get more information about this threat actor.

Advanced hunting

Microsoft Defender customers can run the following advanced hunting queries to find activity associated with Tycoon2FA.

Suspicious sign-in attempts

Find identities potentially compromised by AiTM attacks:

AADSignInEventsBeta
| where Timestamp > ago(7d)
| where IsManaged != 1
| where IsCompliant != 1
//Filtering only for medium and high risk sign-in
| where RiskLevelDuringSignIn in (50, 100)
| where ClientAppUsed == "Browser"
| where isempty(DeviceTrustType)
| where isnotempty(State) or isnotempty(Country) or isnotempty(City)
| where isnotempty(IPAddress)
| where isnotempty(AccountObjectId)
| where isempty(DeviceName)
| where isempty(AadDeviceId)
| project Timestamp,IPAddress, AccountObjectId, ApplicationId, SessionId, RiskLevelDuringSignIn, Browser

Suspicious URL clicks from emails

Look for any suspicious URL clicks from emails by a user before their risky sign-in:

UrlClickEvents
| where Timestamp between (start .. end) //Timestamp around time proximity of Risky signin by user
| where AccountUpn has "" and ActionType has "ClickAllowed"
| project Timestamp,Url,NetworkMessageId

References

• Tycoon 2FA Malware Analysis, Overview by ANY.RUN

Learn more

For the latest security research from the Microsoft Threat Intelligence community, check out the Microsoft Threat Intelligence Blog.

To get notified about new publications and to join discussions on social media, follow us on LinkedIn, X (formerly Twitter), and Bluesky.

To hear stories and insights from the Microsoft Threat Intelligence community about the ever-evolving threat landscape, listen to the Microsoft Threat Intelligence podcast.

The post Inside Tycoon2FA: How a leading AiTM phishing kit operated at scale appeared first on Microsoft Security Blog.

Void Blizzard is a new threat actor Microsoft Threat Intelligence has observed conducting espionage operations primarily targeting organizations that are important to Russian government objectives. These include organizations in government, defense, transportation, media, NGOs, and healthcare, especially in Europe and North America. They often use stolen sign-in details that they likely buy from online marketplaces to gain access to organizations. Once inside, they steal large amounts of emails and files. In April 2025, Microsoft Threat Intelligence observed Void Blizzard begin using more direct methods to steal passwords, such as sending fake emails designed to trick people into giving away their login information.

We thank our partners at Netherlands General Intelligence and Security Service (AIVD) and the Netherlands Defence Intelligence and Security Service (MIVD) for the collaboration on investigating Void Blizzard (also known as LAUNDRY BEAR). You can read their statement here. We also thank our partners at the US Federal Bureau of Investigation for their continued collaboration on investigating Void Blizzard targeting.

Microsoft Threat Intelligence Center has discovered a cluster of worldwide cloud abuse activity conducted by a threat actor we track as Void Blizzard (LAUNDRY BEAR), who we assess with high confidence is Russia-affiliated and has been active since at least April 2024. While Void Blizzard has a global reach, their cyberespionage activity disproportionately targets NATO member states and Ukraine, indicating that the actor is likely collecting intelligence to help support Russian strategic objectives. In particular, the threat actor’s prolific activity against networks in critical sectors poses a heightened risk to NATO member states and allies to Ukraine in general.

Void Blizzard’s cyberespionage operations tend to be highly targeted at specific organizations of interest to the Russian government, including in government, defense, transportation, media, non-governmental organizations (NGOs), and healthcare sectors primarily in Europe and North America. The threat actor uses stolen credentials—which are likely procured from commodity infostealer ecosystems—and collects a high volume of email and files from compromised organizations.

In April 2025, Microsoft Threat Intelligence Center observed Void Blizzard evolving their initial access techniques to include targeted spear phishing for credential theft. While Void Blizzard’s tactics, techniques, and procedures (TTPs) are not unique among advanced persistent threat actors or even Russian nation state-sponsored groups, the widespread success of their operations underscores the enduring threat from even unsophisticated TTPs when leveraged by determined actors seeking to collect sensitive information.

In this report, we share our analysis of Void Blizzard’s targeting and TTPs, with the goal of enabling the broader community to apply specific detections and mitigation guidance to disrupt and protect against Void Blizzard’s operations. We extend our gratitude to our partners at the Netherlands General Intelligence and Security Service (AIVD), the Netherlands Defence Intelligence and Security Service (MIVD), and the US Federal Bureau of Investigation for their collaboration in investigating and raising awareness on Void Blizzard activity and tooling to help organizations disrupt and defend against this threat actor.

Void Blizzard targets

Void Blizzard primarily targets NATO member states and Ukraine. Many of the compromised organizations overlap with past—or, in some cases, concurrent—targeting by other well-known Russian state actors, including Forest Blizzard, Midnight Blizzard, and Secret Blizzard. This intersection suggests shared espionage and intelligence collection interests assigned to the parent organizations of these threat actors. Since mid-2024, Microsoft Threat Intelligence has observed Void Blizzard targeting the following industry verticals, many resulting in successful compromises:

• Communications/Telecommunications
• Defense Industrial Base
• Healthcare
• Education
• Government agencies and services
• Information technology
• Intergovernmental organizations
• Media
• NGOs
• Transportation

Void Blizzard regularly targets government organizations and law enforcement agencies, particularly in NATO member states and especially in countries that provide direct military or humanitarian support to Ukraine. Within Ukraine, Void Blizzard has successfully compromised organizations in multiple sectors, including education, transportation, and defense. In October 2024, Void Blizzard compromised several user accounts at a Ukrainian aviation organization that had been previously targeted by Russian General Staff Main Intelligence Directorate (GRU) actor Seashell Blizzard in 2022. This targeting overlap reflects Russia’s long-standing interest in this organization and, more broadly, in aviation-related organizations since Russia’s invasion of Ukraine in 2022. In 2023, another GRU actor, Forest Blizzard, targeted a prominent aviation organization in Ukraine, and since at least August 2024, it has conducted increasing password spray attacks against several NATO member states’ air traffic control providers.

Tools, tactics, and procedures

Initial access

Void Blizzard conducts opportunistic yet targeted high-volume cyberoperations against targets of intelligence value to the Russian government. Their operations predominately leverage unsophisticated techniques for initial access such as password spray and using stolen authentication credentials. Microsoft assesses that Void Blizzard procures cookies and other credentials through criminal ecosystems. These credentials are then used to gain access to Exchange and sometimes SharePoint Online for information collection.

In April 2025, we identified a Void Blizzard adversary-in-the-middle (AitM) spear phishing campaign that targeted over 20 NGO sector organizations in Europe and the United States. The threat actor used a typosquatted domain to spoof the Microsoft Entra authentication portal. Use of a typosquatted domain to spoof Microsoft Entra authentication was a newly observed initial access tactic for this threat actor. This new tactic suggests that Void Blizzard is augmenting their opportunistic but focused access operations with a more targeted approach, increasing the risk for organizations in critical sectors.

In this campaign, the threat actor posed as an organizer from the European Defense and Security Summit and sent emails containing messages with a PDF attachment that lured targets with a fake invitation to the Summit.

The attachment contained a malicious QR code that redirected to Void Blizzard infrastructure micsrosoftonline[.]com, which hosts a credential phishing page spoofing the Microsoft Entra authentication page. We assess that Void Blizzard is using the open-source attack framework Evilginx to conduct the AitM phishing campaign and steal authentication data, including the input username and password and any cookies generated by the server. Evilginx, publicly released in 2017, was the first widely available phishing kit with AitM capabilities.

Post-compromise activity

Despite the lack of sophistication in their initial access methods, Void Blizzard has been effective in gaining access to and collecting information from compromised organizations in critical sectors.

After gaining initial access, Void Blizzard abuses legitimate cloud APIs, such as Exchange Online and Microsoft Graph, to enumerate users’ mailboxes, including any shared mailboxes, and cloud-hosted files. Once accounts are successfully compromised, the actor likely automates the bulk collection of cloud-hosted data (primarily email and files) and any mailboxes or file shares that the compromised user can access, which can include mailboxes and folders belonging to other users who have granted other users read permissions.

In a small number of Void Blizzard compromises, Microsoft Threat Intelligence has also observed the threat actor accessing Microsoft Teams conversations and messages via the Microsoft Teams web client application. The threat actor has also in some cases enumerated the compromised organization’s Microsoft Entra ID configuration using the publicly available AzureHound tool to gain information about the users, roles, groups, applications, and devices belonging to that tenant.

Mitigation and protection guidance

Microsoft Threat Intelligence recommends organizations that are most likely at risk, primarily those in critical sectors including government and defense, to implement the following recommendations to mitigate against Void Blizzard activity:

Hardening identity and authentication

• Implement a sign-in risk policy to automate response to risky sign-ins. A sign-in risk represents the probability that a given authentication request isn’t authorized by the identity owner. A sign-in risk-based policy can be implemented by adding a sign-in risk condition to Conditional Access policies that evaluate the risk level of a specific user or group. Based on the risk level (high/medium/low), a policy can be configured to block access or force multi-factor authentication.
  • When a user is a high risk and Conditional access evaluation is enabled, the user’s access is revoked, and they are forced to re-authenticate.
  • For regular activity monitoring, use Risky sign-in reports, which surface attempted and successful user access activities where the legitimate owner might not have performed the sign-in.
• Require multifactor authentication (MFA). While certain attacks attempt to circumvent MFA, implementation of MFA remains an essential pillar in identity security and is highly effective at stopping a variety of threats.
  • Leverage phishing-resistant authentication methods such as FIDO Tokens, or Microsoft Authenticator with passkey. Avoid telephony-based MFA methods to avoid risks associated with SIM-jacking.
• Centralize your organization’s identity management into a single platform. If your organization is a hybrid environment, integrate your on-premises directories with your cloud directories. If your organization is using a third-party for identity management, ensure this data is being logged in a SIEM or connected to Microsoft Entra to fully monitor for malicious identity access from a centralized location. The added benefits to centralizing all identity data is to facilitate implementation of Single Sign On (SSO) and provide users with a more seamless authentication process, as well as configure Microsoft Entra ID’s machine learning models to operate on all identity data, thus learning the difference between legitimate access and malicious access quicker and easier. It is recommended to synchronize all user accounts except administrative and high privileged ones when doing this to maintain a boundary between the on-premises environment and the cloud environment, in case of a breach.
• Secure accounts with credential hygiene: practice the principle of least privilege and audit privileged account activity in your Entra ID environments to slow and stop attackers.

Hardening email security

• Manage mailbox auditing to ensure actions performed by mailbox owners, delegates, and admins are automatically logged. New mailboxes should already have this feature turned on by default.
• Run a non-owner mailbox access report in the Exchange Admin Center to detect unauthorized access onto a mailbox.

Hardening against post-compromise activity

• If a breach or compromise via commodity info stealer is suspected, ensure that any accounts that may have been accessed by that machine have their credentials rotated in addition to removing the malware. Given the widespread use of infostealers in attacks, organizations should immediately respond to infostealer activity and mitigate the risk of credential theft to prevent follow-on malicious activity.
• Conduct an audit search in the Microsoft Graph API for anomalous activity.
• Create Defender for Cloud Apps anomaly detection policies.
• Prevent, detect or investigate possible token theft activity by reviewing mitigation techniques.
• If you suspect password spray activity against your organization’s networks, you can refer to this guide for password spray investigation.

Microsoft Defender XDR detections

Microsoft Defender XDR customers can refer to the list of applicable detections below. Microsoft Defender XDR coordinates detection, prevention, investigation, and response across endpoints, identities, email, apps to provide integrated protection against attacks like the threat discussed in this blog.

Customers with provisioned access can also use Microsoft Security Copilot in Microsoft Defender to investigate and respond to incidents, hunt for threats, and protect their organization with relevant threat intelligence.

Microsoft Defender for Endpoint

The following alert indicates threat actor activity related to Void Blizzard. Note, however, that this alert can be also triggered by Void Blizzard activity that is not related to the activity covered in this report.

• Void Blizzard activity

The following alerts might indicate credential theft activity related to Void Blizzard utilizing commodity information stealers or conducting password spraying techniques. Note, however, that these alerts can be also triggered by unrelated threat activity.

• Information stealing malware activity
• Password spraying

Microsoft Defender for Identity

The following Microsoft Defender for Identity alerts can indicate associated threat activity. Note, however, that these alerts can be also triggered by unrelated threat activity.

• Password Spray
• Unfamiliar Sign-in properties
• Atypical travel
• Suspicious behavior: Impossible travel activity

Microsoft Defender for Cloud Apps

The following Microsoft Defender for Cloud Apps alerts can indicate associated threat activity. Note, however, that these alerts can be also triggered by unrelated threat activity.

• Impossible travel
• Activity from suspicious IP addresses
• Unusual activities (by user)

Microsoft Defender for Cloud

The following alerts might also indicate threat activity associated with this threat. These alerts, however, can be triggered by unrelated threat activity and are not monitored in the status cards provided with this report.

• AzureHound tool invocation detected
• Communication with possible phishing domain
• Communication with suspicious domain identified by threat intelligence

Microsoft Entra ID Protection

The following Microsoft Entra ID Protection risk detections inform Entra ID user risk events and can indicate associated threat activity, including unusual user activity consistent with known attack patterns identified by Microsoft Threat Intelligence research. Note, however, that these alerts can be also triggered by unrelated threat activity.

• Anomalous Token (sign-in) (RiskEventType: anomalousToken)
• Password spray (RiskEventType: passwordSpray)
• Anomalous Token (user) (RiskEventType: anomalousToken)
• Attacker in the Middle (RiskEventType: attackerinTheMiddle)
• Activity from Anonymous IP address (RiskEventType: anonymizedIPAddress)
• Microsoft Entra threat intelligence (sign-in): (RiskEventType: investigationsThreatIntelligence)
• Suspicious API Traffic (RiskEventType: suspiciousAPITraffic)

Microsoft Security Copilot

Security Copilot customers can use the standalone experience to create their own prompts or run the following pre-built promptbooks to automate incident response or investigation tasks related to this threat:

• Incident investigation
• Microsoft User analysis
• Threat actor profile
• Threat Intelligence 360 report based on MDTI article
• Vulnerability impact assessment

Note that some promptbooks require access to plugins for Microsoft products such as Microsoft Defender XDR or Microsoft Sentinel.

Threat intelligence reports

Microsoft customers can use the following reports in Microsoft products to get the most up-to-date information about the threat actor, malicious activity, and techniques discussed in this blog. These reports provide the intelligence, protection information, and recommended actions to prevent, mitigate, or respond to associated threats found in customer environments.

Microsoft Defender Threat Intelligence

• Void Blizzard

Microsoft Security Copilot customers can also use the Microsoft Security Copilot integration in Microsoft Defender Threat Intelligence, either in the Security Copilot standalone portal or in the embedded experience in the Microsoft Defender portal to get more information about this threat actor.

Hunting queries

Microsoft Defender XDR

Microsoft Defender XDR customers can find related Void Blizzard spear phishing activity related to this threat in their networks by running the following queries.

Possible phishing email targets

The following query can help identify possible email targets of Void Blizzard’s spear phishing attempts

EmailEvents
| where SenderFromDomain in~ ("ebsumrnit.eu")
| project SenderFromDomain, SenderFromAddress, RecipientEmailAddress, Subject, Timestamp

Communication with Void Blizzard domain

The following query can help surface devices that might have communicated with Void Blizzard’s spear phishing domain:

let domainList = dynamic(["micsrosoftonline.com", "outlook-office.micsrosoftonline.com"]);
union
(
    DnsEvents
    | where QueryType has_any(domainList) or Name has_any(domainList)
    | project TimeGenerated, Domain = QueryType, SourceTable = "DnsEvents"
),
(
    IdentityQueryEvents
    | where QueryTarget has_any(domainList)
    | project Timestamp, Domain = QueryTarget, SourceTable = "IdentityQueryEvents"
),
(
    DeviceNetworkEvents
    | where RemoteUrl has_any(domainList)
    | project Timestamp, Domain = RemoteUrl, SourceTable = "DeviceNetworkEvents"
),
(
    DeviceNetworkInfo
    | extend DnsAddresses = parse_json(DnsAddresses), ConnectedNetworks = parse_json(ConnectedNetworks)
    | mv-expand DnsAddresses, ConnectedNetworks
    | where DnsAddresses has_any(domainList) or ConnectedNetworks.Name has_any(domainList)
    | project Timestamp, Domain = coalesce(DnsAddresses, ConnectedNetworks.Name), SourceTable = "DeviceNetworkInfo"
),
(
    VMConnection
    | extend RemoteDnsQuestions = parse_json(RemoteDnsQuestions), RemoteDnsCanonicalNames = parse_json(RemoteDnsCanonicalNames)
    | mv-expand RemoteDnsQuestions, RemoteDnsCanonicalNames
    | where RemoteDnsQuestions has_any(domainList) or RemoteDnsCanonicalNames has_any(domainList)
    | project TimeGenerated, Domain = coalesce(RemoteDnsQuestions, RemoteDnsCanonicalNames), SourceTable = "VMConnection"
),
(
    W3CIISLog
    | where csHost has_any(domainList) or csReferer has_any(domainList)
    | project TimeGenerated, Domain = coalesce(csHost, csReferer), SourceTable = "W3CIISLog"
),
(
    EmailUrlInfo
    | where UrlDomain has_any(domainList)
    | project Timestamp, Domain = UrlDomain, SourceTable = "EmailUrlInfo"
),
(
    UrlClickEvents
    | where Url has_any(domainList)
    | project Timestamp, Domain = Url, SourceTable = "UrlClickEvents"
)
| order by TimeGenerated desc

Microsoft Sentinel

The Microsoft blog Web Shell Threat Hunting with Azure Sentinel provides hunting queries and techniques for Sentinel-specific threat hunting. Several hunting queries are also available below. 

NOTE: Microsoft Sentinel customers can use the following queries to detect phishing attempts and email exfiltration attempts via Graph API. While these queries are not specific to threat actors, they can help you stay vigilant and safeguard your organization from phishing attacks. These queries search for a week’s worth of events. To explore up to 30 days’ worth of raw data to inspect events in your network and locate potentially related indicators for more than a week, go to the Advanced hunting page > Query tab, select the calendar dropdown menu to update your query to hunt for the Last 30 days.

If a query provides high value insights into possible malicious or otherwise anomalous behavior, you can create a custom detection rule based on that query and surface those insights as custom alerts. To do this in the Defender XDR portal, run the query in the Advanced hunting page and select Create detection rule. To do this in the Sentinel portal, use hunting capabilities to run and view the query’s results, then select New alert rule > Create Microsoft Sentinel alert.

Campaign with suspicious keywords

In this detection, we track emails with suspicious keywords in subjects.

let PhishingKeywords = ()
  {pack_array("account", "alert", "bank", "billing", "card", "change", "confirmation","login", "password", "mfa", "authorize", "authenticate", "payment", "urgent", "verify", "blocked");};
  EmailEvents
  | where Timestamp > ago(1d)
  | where EmailDirection == "Inbound"
  | where DeliveryAction == "Delivered"
  | where isempty(SenderObjectId)
  | where Subject has_any (PhishingKeywords())

Determine successfully delivered phishing emails to Inbox/Junk folder

This query identifies threats which got successfully delivered to Inbox/Junk folder.

EmailEvents
  | where isnotempty(ThreatTypes) and DeliveryLocation in~ ("Inbox/folder","Junk folder")
  | extend Name = tostring(split(SenderFromAddress, '@', 0)[0]), UPNSuffix = tostring(split(SenderFromAddress, '@', 1)[0])
  | extend Account_0_Name = Name
  | extend Account_0_UPNSuffix = UPNSuffix
  | extend IP_0_Address = SenderIPv4
  | extend MailBox_0_MailboxPrimaryAddress = RecipientEmailAddress

Successful sign-in from phishing link

This content is employed to correlate with Microsoft Defender XDR phishing-related alerts. It focuses on instances where a user successfully connects to a phishing URL from a non-Microsoft network device and subsequently makes successful sign-in attempts from the phishing IP address.

let Alert_List= dynamic([
    "Phishing link click observed in Network Traffic",
    "Phish delivered due to an IP allow policy",
    "A potentially malicious URL click was detected",
    "High Risk Sign-in Observed in Network Traffic",
    "A user clicked through to a potentially malicious URL",
    "Suspicious network connection to AitM phishing site",
    "Messages containing malicious entity not removed after delivery",
    "Email messages containing malicious URL removed after delivery",
    "Email reported by user as malware or phish",
    "Phish delivered due to an ETR override",
    "Phish not zapped because ZAP is disabled"]);
    SecurityAlert
    | where AlertName in~ (Alert_List)
    //Findling Alerts which has the URL
    | where Entities has "url"
    //extracting Entities
    | extend Entities = parse_json(Entities)
    | mv-apply Entity = Entities on
        (
        where Entity.Type == 'url'
        | extend EntityUrl = tostring(Entity.Url)
        )
    | summarize
        Url=tostring(tolower(take_any(EntityUrl))),
        AlertTime= min(TimeGenerated),
        make_set(SystemAlertId, 100)
        by ProductName, AlertName
    // matching with 3rd party network logs and 3p Alerts
    | join kind= inner (CommonSecurityLog
        | where DeviceVendor has_any  ("Palo Alto Networks", "Fortinet", "Check Point", "Zscaler")
        | where DeviceProduct startswith "FortiGate" or DeviceProduct startswith  "PAN" or DeviceProduct startswith  "VPN" or DeviceProduct startswith "FireWall" or DeviceProduct startswith  "NSSWeblog" or DeviceProduct startswith "URL"
        | where DeviceAction != "Block"
        | where isnotempty(RequestURL)
        | project
            3plogTime=TimeGenerated,
            DeviceVendor,
            DeviceProduct,
            Activity,
            DestinationHostName,
            DestinationIP,
            RequestURL=tostring(tolower(RequestURL)),
            MaliciousIP,
            SourceUserName=tostring(tolower(SourceUserName)),
            IndicatorThreatType,
            ThreatSeverity,
            ThreatConfidence,
            SourceUserID,
            SourceHostName)
        on $left.Url == $right.RequestURL
    // matching successful Login from suspicious IP
    | join kind=inner (SigninLogs
        //filtering the Successful Login
        | where ResultType == 0
        | project
            IPAddress,
            SourceSystem,
            SigniningTime= TimeGenerated,
            OperationName,
            ResultType,
            ResultDescription,
            AlternateSignInName,
            AppDisplayName,
            AuthenticationRequirement,
            ClientAppUsed,
            RiskState,
            RiskLevelDuringSignIn,
            UserPrincipalName=tostring(tolower(UserPrincipalName)),
            Name = tostring(split(UserPrincipalName, "@")[0]),
            UPNSuffix =tostring(split(UserPrincipalName, "@")[1]))
        on $left.DestinationIP == $right.IPAddress and $left.SourceUserName == $right.UserPrincipalName
    | where SigniningTime between ((AlertTime - 6h) .. (AlertTime + 6h)) and 3plogTime between ((AlertTime - 6h) .. (AlertTime + 6h))

Phishing link click observed in network traffic

The purpose of this content is to identify successful phishing links accessed by users. Once a user clicks on a phishing link, we observe successful network activity originating from non-Microsoft network devices.

//Finding MDO Security alerts and extracting the Entities user, Domain, Ip, and URL.
    let Alert_List= dynamic([
    "Phishing link click observed in Network Traffic",
    "Phish delivered due to an IP allow policy",
    "A potentially malicious URL click was detected",
    "High Risk Sign-in Observed in Network Traffic",
    "A user clicked through to a potentially malicious URL",
    "Suspicious network connection to AitM phishing site",
    "Messages containing malicious entity not removed after delivery",
    "Email messages containing malicious URL removed after delivery",
    "Email reported by user as malware or phish",
    "Phish delivered due to an ETR override",
    "Phish not zapped because ZAP is disabled"]);
    SecurityAlert
    |where ProviderName in~ ("Office 365 Advanced Threat Protection", "OATP")
    | where AlertName in~ (Alert_List)
    //extracting Alert Entities
     | extend Entities = parse_json(Entities)
    | mv-apply Entity = Entities on
    (
    where Entity.Type == 'account'
    | extend EntityUPN = iff(isempty(Entity.UserPrincipalName), tostring(strcat(Entity.Name, "@", tostring (Entity.UPNSuffix))), tostring(Entity.UserPrincipalName))
    )
    | mv-apply Entity = Entities on
    (
    where Entity.Type == 'url'
    | extend EntityUrl = tostring(Entity.Url)
    )
    | summarize AccountUpn=tolower(tostring(take_any(EntityUPN))),Url=tostring(tolower(take_any(EntityUrl))),AlertTime= min(TimeGenerated)by SystemAlertId, ProductName
    // filtering 3pnetwork devices
    | join kind= inner (CommonSecurityLog
    | where DeviceVendor has_any  ("Palo Alto Networks", "Fortinet", "Check Point", "Zscaler")
    | where DeviceAction != "Block"
    | where DeviceProduct startswith "FortiGate" or DeviceProduct startswith  "PAN" or DeviceProduct startswith  "VPN" or DeviceProduct startswith "FireWall" or DeviceProduct startswith  "NSSWeblog" or DeviceProduct startswith "URL"
    | where isnotempty(RequestURL)
    | where isnotempty(SourceUserName)
    | extend SourceUserName = tolower(SourceUserName)
    | project
    3plogTime=TimeGenerated,
    DeviceVendor,
    DeviceProduct,
    Activity,
    DestinationHostName,
    DestinationIP,
    RequestURL=tostring(tolower(RequestURL)),
    MaliciousIP,
    Name = tostring(split(SourceUserName,"@")[0]),
    UPNSuffix =tostring(split(SourceUserName,"@")[1]),
    SourceUserName,
    IndicatorThreatType,
    ThreatSeverity,AdditionalExtensions,
    ThreatConfidence)on $left.Url == $right.RequestURL and $left.AccountUpn == $right.SourceUserName
    // Applied the condition where alert trigger 1st and then the 3p Network activity execution
    | where AlertTime between ((3plogTime - 1h) .. (3plogTime + 1h))

Suspicious URL clicked

This query correlates Microsoft Defender for Office 365 signals and Microsoft Entra ID identity data to find the relevant endpoint event BrowerLaunchedToOpen in Microsoft Defender ATP. This event reflects relevant clicks on the malicious URL in the spear phishing email recognized by Microsoft Defender for Office 365.

// Some URLs are wrapped with SafeLinks
// Let's get the unwrapped URL and clicks 
  AlertInfo
  | where ServiceSource =~ "Microsoft Defender for Office 365"
  | join (
          AlertEvidence
          | where EntityType =="Url"
          | project AlertId, RemoteUrl 
      )
      on AlertId
  | join (
          AlertEvidence
          | where EntityType =="MailMessage"
          | project AlertId, NetworkMessageId 
      )
      on AlertId
  // Get the unique NetworkMessageId for the email containing the Url
  | distinct RemoteUrl, NetworkMessageId
  | join EmailEvents on NetworkMessageId
  // Get the email RecipientEmailAddress and ObjectId from the email 
  | distinct RemoteUrl, NetworkMessageId, RecipientEmailAddress , RecipientObjectId
  | join kind = inner IdentityInfo on $left.RecipientObjectId  == $right.AccountObjectId 
  // get the UserSid of the Recipient
  | extend OnPremSid = AccountSID
  | distinct RemoteUrl, NetworkMessageId, RecipientEmailAddress , RecipientObjectId, OnPremSid 
  // Get the Url click event on the recipient device.
  | join kind = inner  
      (DeviceEvents 
      | where ActionType == "BrowserLaunchedToOpenUrl"| where isnotempty(RemoteUrl) 
      | project UrlDeviceClickTime = Timestamp , UrlClickedByUserSid = RemoteUrl, 
                  InitiatingProcessAccountSid, DeviceName, DeviceId, InitiatingProcessFileName
      ) 
     on $left.OnPremSid == $right.InitiatingProcessAccountSid and $left.RemoteUrl == $right.UrlClickedByUserSid
  | distinct UrlDeviceClickTime, RemoteUrl, NetworkMessageId, RecipientEmailAddress, RecipientObjectId, 
      OnPremSid, UrlClickedByUserSid, DeviceName, DeviceId, InitiatingProcessFileName 
  | sort by UrlDeviceClickTime desc

Anomalies in MailItemAccess by GraphAPI

This query looks for anomalies in mail item access events made by Graph API. It uses standard deviation to determine if the number of events is anomalous.

let starttime = 30d;
  let STDThreshold = 2.5;
  let allMailAccsessByGraphAPI = CloudAppEvents
  | where   ActionType == "MailItemsAccessed"
  | where Timestamp between (startofday(ago(starttime))..now())
  | where isnotempty(RawEventData['ClientAppId'] ) and RawEventData['AppId'] has "00000003-0000-0000-c000-000000000000"
  | extend ClientAppId = tostring(RawEventData['ClientAppId'])
  | extend OperationCount = toint(RawEventData['OperationCount'])
  | project Timestamp,OperationCount , ClientAppId;
  let calculateNumberOfMailPerDay = allMailAccsessByGraphAPI
  | summarize NumberOfMailPerDay =sum(toint(OperationCount)) by ClientAppId,format_datetime(Timestamp, 'y-M-d');
  let calculteAvgAndStdev=calculateNumberOfMailPerDay
  | summarize avg=avg(NumberOfMailPerDay),stev=stdev(NumberOfMailPerDay) by ClientAppId;
  calculteAvgAndStdev  | join calculateNumberOfMailPerDay on ClientAppId
  | sort by ClientAppId
  |  where NumberOfMailPerDay > avg + STDThreshold * stev
  | project ClientAppId,Timestamp,NumberOfMailPerDay,avg,stev

Indicators of compromise

Learn more

For the latest security research from the Microsoft Threat Intelligence community, check out the Microsoft Threat Intelligence Blog: https://aka.ms/threatintelblog.

To get notified about new publications and to join discussions on social media, follow us on LinkedIn at https://www.linkedin.com/showcase/microsoft-threat-intelligence, on X (formerly Twitter) at https://x.com/MsftSecIntel, and on Bluesky at https://bsky.app/profile/threatintel.microsoft.com.

To hear stories and insights from the Microsoft Threat Intelligence community about the ever-evolving threat landscape, listen to the Microsoft Threat Intelligence podcast: https://thecyberwire.com/podcasts/microsoft-threat-intelligence.

The post New Russia-affiliated actor Void Blizzard targets critical sectors for espionage appeared first on Microsoft Security Blog.

I recently worked with an enterprise customer who experienced a data exfiltration attack using the characteristics of the BazaCall campaign. BazaCall can be both a ransomware and data exfiltration attack that are used together to increase pressure on and damage to the victim. Microsoft Purview has data security capabilities that form part of a holistic mitigation strategy.

Microsoft 365 Defender is our security solution for phishing and related cyberthreats. Some great analysis has been done by the Microsoft Threat Intelligence team on BazaCall’s Tactics, Techniques, and Procedures (TTPs). They’ve also shared how to use Microsoft 365 Defender to locate exploitation activity.

I wanted to take another perspective with this post and share the role that Microsoft Purview data security solutions play, together with Microsoft 365 Defender and Microsoft Sentinel, to provide defense-in-depth mitigation. With defense-in-depth, we create barriers to the bad actor, increasing their resources required and uncertainty, interfering with their business case.

Microsoft Purview provides important value with unified data governance and compliance solutions but it’s Microsoft Purview’s data security capabilities within Microsoft 365 we’ll be discussing in this blog.

What makes BazaCall different from most phishing attacks is using a malicious email to have the victim initiate a call to a phony call center run by the bad actor that then coaches the victim to install malware. Replacing malicious links and attachments in email with a phone number to the call center is used to evade email protection.

An overview of the BazaCall attack flow is provided at the end of this post.

The mitigations suggested here will be of value for attacks where the bad actor has control of a Microsoft 365 account and is attempting to exfiltrate sensitive data.

The data security benefits of Microsoft Purview for attack mitigation are sometimes overlooked. These solutions may be managed by other groups in the organization, such as the compliance team rather than the security team, and so may not be the go-to tools in the toolbox when preparing for or responding to an attack. These solutions should be part of a defense-in-depth strategy and Zero Trust architecture.

Microsoft Purview Mitigations

Microsoft Purview Information Protection sensitivity labels can be applied to protect sensitive files from unauthorized access. These sensitivity labels can have scoped encryption, among other protections, which travels with the file inside and outside of the organization’s environment. This would make the file unreadable except by the party for which the encryption is scoped—for example, only employees, a partner, or a customer organization—or it can be defined by the user to be consumable only by specific individuals.

Figure 1. Sensitivity Label with scoped encryption—accessible only to employees.

Automation, configured by the administrators, can be used to support the user in applying these labels including making the application of a label mandatory if the file contains sensitive information.

Microsoft Purview Data Loss Prevention (Purview DLP) can be used to prevent the sensitive information from being exfiltrated through several egress channels, including user’s endpoint devices, Microsoft cloud services such as SharePoint Online, OneDrive for Business, Exchange Online, Teams, and Microsoft PowerBI, browsers such as Microsoft Edge, Chrome, and Firefox, as well as non-Microsoft applications such as Salesforce, Dropbox, Box, and more, including the free file-sharing services used as part of the BazaCall TTPs.

Customers can create policies that block and do not allow override for their top priority sensitive information such that even if the bad actor manages to get access to the user’s account, they are blocked from exfiltrating any sensitive content. Purview DLP policies can be configured leveraging a variety of out-of-the-box or custom criteria including machine learning-based trainable classifiers as well as the sensitivity labels created in Information Protection.

Figure 2. Purview DLP preventing the upload of sensitive files into Dropbox.

Microsoft Purview Insider Risk Management can alert the security team to the bad actor’s activities, including the exfiltration of sensitive information to the file-sharing service. Insider Risk Management can reason over and parse through user activity signals, by leveraging more than 100 ready-to-use indicators and machine learning models, including sequence detection and cumulative exfiltration detection. With Adaptive Protection powered by Insider Risk Management, the security team can detect high-risk actors, such as a bad actor-controlled account, and automatically enforce the strictest DLP policy to prevent them from exfiltrating data.  

Figure 3. Insider Risk Management uses specialized algorithms and machine learning to identify data exfiltration and other risks.

Microsoft Defender for Cloud Apps can make a file-sharing site used for sensitive file exfiltration unreachable from the user’s browser or it can prevent sensitive files from being moved to the site. Alternatively, the policy can be configured to only allow files to be moved to the file-sharing site if they have a sensitivity label applied that contains scoped encryption. If this protected file is exfiltrated it would not be readable by the bad actor.

Figure 4. Microsoft Defender for Cloud Apps blocking access to file sharing and backup site.

Microsoft Purview Audit provides forensic information to scope a possible breach. This is especially valuable when bad actors are “living off the land.” Among the audit items made available are the terms that a user searched in email and SharePoint. If the bad actor was searching for sensitive information to exfiltrate, this item will assist the investigation.

Purview Audit, recently expanded for accessibility and flexibility, will also provide insight to mail items accessed and mail sent, which would be impactful when investigating scope and possible exfiltration channels. Although a bad actor’s known TTPs may not include these channels, we need a fulsome investigation. Their TTPs are likely not static.

Purview Audit Premium provides more logging event retention capabilities, with one-year retention (up from 180 days with Standard) and an option to increase retention to 10 years among other upgraded features.

Figure 5. Premium Audit solution searching forensic events.

Microsoft Purview Data Lifecycle Management policies and labeling could be used to purge unneeded information from the organization’s environment. An auditable review can be required prior to deletion or deletion can be automated without user or administrator action.

If information is not in the environment, it cannot be exfiltrated by the bad actor or put the organization at risk.

Figure 6. Disposal of unneeded documents reduces exfiltration risk to the organization.

About BazaCall

BazaCall uses a phishing campaign that tricks unsuspecting users into phoning the attacker, who coaches them into downloading BazaLoader malware, which retrieves and installs a remote monitoring and management (RMM) tool onto the user’s device. The email typically claims that the user has reached the end of a free trial of some type, that billing will begin shortly and provides an option to cancel by phoning a call center. The threat of unjustified billing is the lever that the attacker uses to get the victim to comply.

Typically, the file download has been a malicious Excel document that purports to be a “cancellation form” for the unwanted service and charges referred to in the phishing campaign. The bad actor coaches the victim into accepting macros and disabling security solutions to complete the phony “cancellation.”

RMM software provides multiple useful purposes for attackers: The software allows an attacker to maintain persistence and deploy malicious tools within a compromised network. It can also be used for an interactive command-and-control system. With command and control established, the bad actor organization can spread laterally through the environment to steal sensitive data and deploy ransomware. Once command and control of the user’s machine is established, bad actor hands-on keyboard is used to exfiltrate data including through free cloud-based file-sharing sites. TTPs have evolved in the last two years, including the use of file-sharing sites for exfiltration in addition to open-source tools like RClone.

The user is also subject to human-operated ransomware.

The mitigations discussed in this post are focused on the data exfiltration aspects in the “hands-on-keyboard” phase of the attack.

Figure 7. BazaCall attack flow.

Microsoft Purview can help protect from BazaCall attacks

Microsoft Purview data security for Microsoft 365 is not a cure-all for phishing attacks. It is part of a defense-in-depth strategy that includes user training, antimalware, vulnerability management, email security, access control, monitoring, and response. The data security solutions within Microsoft Purview should be considered based on risk-based criteria for inclusion in the strategy.

These tools may be managed by different teams in the organization. Collaboration among these teams is critical for coordinated defense and incident response. 

Learn more

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us on LinkedIn (Microsoft Security) and Twitter (@MSFTSecurity) for the latest news and updates on cybersecurity.

The post Microsoft Purview data security mitigations for BazaCall and other human-operated data exfiltration attacks appeared first on Microsoft Security Blog.

Eighty-two percent of breaches include (and often start with) user behavior.¹ Not all are phishing, but a majority of them are just that. Phishing is, and has been for many years, the cheapest and most reliable way for an attacker of any motivation (nation-state actors down to simple script-kiddie scammers) to establish a toehold in an organization. Social engineering and phishing are used for initial breach tactics, lateral movement, and elevation of privilege, and, in many cases, they directly lead to data exfiltration.

Worse, breaches cost companies a lot of time and money. Several security research companies have determined that the average data breach costs a company about USD4 million per incident.² Averting even a handful of breach events in any given year can save you millions of dollars and thousands of hours of valuable security operators’ time.

So, how does behavior play into this? Doesn’t my company spend a bunch of money every year on technical solutions to prevent those phishing attacks from making it through? Don’t we have detection and response capabilities that find and fix those breaches quickly? Any organization that cares about its data certainly should invest in exactly those capabilities, but the strategy is incomplete for a few reasons:

• Technical solutions never have and likely never will provide perfect protection. Humans are capable of incredibly creative and intuitive thinking. Attackers with even a passing understanding of how protective solutions work can easily find gaps and workarounds. Decades of breaches have shown us that any determined attacker will find a way in. Assume breach principles hold that organizations should assume that their ecosystems are breached, that they should not automatically trust their existing protection boundaries, and that they should invest in detection and response mechanisms in equal measure to prevention. This, Microsoft believes, is the most effective approach to mitigating organizational risk.
• Humans are the most valuable part of any organization’s mission. They make all the data. They derive all the most valuable insights. They integrate and maintain all the complicated systems that make up any modern enterprise. An attacker can go after systems to get to data, but the inherent fallibility of humans provides a much more malleable target. You can’t insulate the people in your organization from that risk because they are almost always the ones responsible for creating the asset in the first place. Attackers know that and almost always incorporate social engineering into their plans.
• Human behavior, especially as it relates to risk, is an incredibly complicated and nuanced process. It is probabilistic in nature, and attackers know that. Factors include the context in which the behavioral choice is made, the knowledge of the human, the attitudes and motivations of the person, externalities such as time pressures and adjacent choices, and the past experience of the human. Any of those factors can change day-to-day, and so a phishing attack that a user correctly identifies and avoids might not work today but would fail to detect in some other context.

With that in mind, in partnership with Microsoft, Terranova created the Gone Phishing Tournament, an online phishing initiative that uses real-world simulations to establish accurate phishing clickthrough rates and additional benchmarking statistics for user behaviors. With this opportunity, you will be able to drive effective behavior change and build a strong security-aware organizational culture with free, in-depth phishing simulation benchmarking data.

Given this context, why should an organization care about user behavior? One reason is that even small changes in behavior can result in significant reductions in risk and every data breach you avoid saves you literal millions of dollars. Admittedly, behavior change is hard. The security awareness business has been working to help educate users for decades now, and the human behavior risk portion of the overall risk pie remains large. We think the capabilities that modern solutions are bringing to bear are the beginning of a major shift in the industry. Some key capabilities to consider:

• You must measure something to move it. Phish susceptibility assessment is a core part of any security awareness program, and we think authentic simulation is the best way to measure real-world phishing risk behavior.
• Teaching is more than just telling. One of the reasons why effective security awareness programs focus so much on simulation is because it gives users the experience of an attack (safely). Doing something hands-on and experiencing it directly sticks in human brains much more effectively than just seeing or hearing a description of it.
• Life in organizations already includes a lot of formal learning, so you must find new, differentiated, and contextual ways to engage your people in learning experiences. Games, nudges, and social rewards systems educate without lecturing and bring an element of fun that helps the important messages stick.
• Everybody is at a different place in their journey. Look for solutions that allow you to differentiate learning based on what the user already knows, or what you think is going to be especially problematic for them.
• Security Awareness training has evolved most commonly to be a twice-yearly simulation with a five- to seven-minute video. This formula is usually manageable by organizations to execute, but it rarely produces desired results. Look for solutions that give you the ability to vary the frequency, targeting variations, payload variability, and training experiences. Some of your people might just need reminders twice a year, but many will need more frequent experiences to maintain behavioral alignment.

Every major organization on earth is in the same boat. User behavior risk is high, difficult to change, and exploited every day by attackers. Take the time to learn from each other. Participate in conferences. Make connections with people at other companies that are doing the same role. Engage with the solutions that you leverage and give those product teams feedback about what is and is not working. 

Knowledge is power when it comes to being cybersmart, and there are many ways to prepare yourself and your organization to be safer online and fight cyber threats. October will be Cybersecurity Awareness Month, and you will be able to take advantage of Microsoft’s expertise with several resources that will be made available by Microsoft Security.  

Stay tuned for Microsoft’s best practices on Cybersecurity Awareness Month and don’t forget to register for Terranova Security Gone Phishing Tournament. Let’s #BeCyberSmart together! 

Learn more

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us at @MSFTSecurity for the latest news and updates on cybersecurity.

¹2022 Data Breach Investigations Report, Verizon. 2022.

²How Much Does a Data Breach Cost?, Embroker. September 2, 2022.

The post Test your team’s security readiness with the Gone Phishing Tournament appeared first on Microsoft Security Blog.

Tournament results

Terranova Security’s Gone Phishing Tournament is a free, annual cybersecurity event that takes place in October to coincide with National Cybersecurity Awareness Month. The Tournament tests real-world responses using a phishing email modeled on actual threats provided by Attack Simulation Training in Microsoft Defender for Office 365 (Office 365 Advanced Threat Protection). Click rates are segmented by industry, organization size, region, web browser, and operating system.

Using a template created from real phishing attacks, translated into 11 languages across 98 countries, the 2020 Gone Phishing Tournament revealed that organizations are taking phishing threats seriously, but with mixed results.

“There’s increasing crossover between our personal and work activities online. That’s why cybersecurity education and training needs to be an ongoing commitment.”—Vasu Jakkal, CVP, Security, Compliance and Identity Marketing, Microsoft

Figure 1: Password submission by industry

The average password submission rate across industries was 13.4 percent, with education employees taking the bait least often at just 7.9 percent. The highest password submission rate was among public sector employees at 20.7 percent.

Figure 2: Click and password submission rates by the size of the organization

The tournament results also showed there was not a great deal of variation when comparing organizations of varied sizes. For example, there was only a 9.2 percent difference in the number of people who clicked the phishing link and submitted passwords at organizations of fewer than 100 people, compared with those consisting of more than 3,000 employees. The results show that phishing attacks are not just a threat for smaller organizations with less sophisticated cybersecurity training—large organizations were even more vulnerable.

Ongoing attacks

In the new world of remote work, your people are your perimeter. Phishing provides hackers with a low-cost, low-risk form of social engineering with a potentially big payoff in the form of stolen passwords, leaked credentials, and access to sensitive data and intellectual property. Throughout 2020, opportunistic cybercriminals have been preying on distracted, overstressed remote workers by introducing COVID-19-themed phishing lures. The World Health Organization (WHO) has referred to the ongoing COVID-19 themed phishing attacks as an “infodemic.” By the summer of 2020, the Federal Trade Commission (FTC) had already recorded over 59,000 coronavirus or stimulus-related complaints resulting in over $74 million in losses.

The National Cyber Security Alliance (NCSA) is pushing back against the rise in cybercrime by building strong public and private partnerships that empower users to stay secure online.

“The Phishing Benchmark Global Report reinforces the need for the current work being done by organizations like Microsoft, Terranova Security, and the National Cyber Security Alliance. Real-world phishing simulations and engaging security awareness training help make organizations, employees, and everyday citizens aware of the growing risk of social engineering and phishing emails. We will continue working in partnership with industry and government to empower the global community towards becoming one that is more cyber aware.”—Kelvin Coleman, Executive Director of NCSA

Not all security awareness training is alike

To defend against increasingly sophisticated cyber threats, organizations need real-world training as a comprehensive internal campaign. Terranova Security Awareness Training includes gamification and interactive sessions designed to engage and can be localized to different geographies around the world.

Attack Simulation Training in Microsoft Defender for Office 365, delivered in partnership with Terranova Security, integrates simulations, training, and reporting. Terranova Security is excited to partner with Microsoft to deliver this differentiated, industry-leading solution, allowing our customers to detect, prioritize, and remediate phishing risk across their organizations. With Attack simulation training, customers can:

• Simulate real threats: Detect vulnerabilities with real lures and templates—automatically or manually send employees the phishing emails attackers have used against your organization. Then, reach out to users who fall for a phishing lure with personalized training content.
• Remediate intelligently: Quantify social engineering risks across employees and threat vectors to prioritize remedial training. Track your organization’s progress against a baseline and measure the behavioral impacts. Using user susceptibility metrics triggers automated repeat offender simulations and training for people who need extra attention.
• Improve security posture: Reinforce your human security system with targeted training designed to change employee behavior. Training can be customized and localized, including simulations tailored to your employee’s contexts—region, industry, function—with granular conditionality on harvesting. Cater to diverse learning styles with interactive nano-learning and micro-learning content.

If there is a common thread to be found in this year’s Gone Phishing Tournament results, it is that organizations of every size need to make integrated attack simulation and training a cornerstone of their cybersecurity program. Cybercriminals do not take days off, and neither should your simulation and training program.

To learn more about Microsoft Security solutions visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us at @MSFTSecurity for the latest news and updates on cybersecurity.

The post Terranova Security Gone Phishing Tournament reveals continued weak spot in cybersecurity appeared first on Microsoft Security Blog.

Cybercriminals have ramped up their initial compromises through phishing and pharming attacks using a variety of tools and tactics that, while numerous, are simple and often go undetected. One technique that attackers continue to leverage to obfuscate their activity and remain undetected is dwell time.

Dwell is the time between the initial compromise and the point when the attack campaign is identified. While industry reports offer differing averages for dwell time, I have yet to see reporting that presents an average below the 50 to 60-day range. Read more about advanced endpoint protection and dwell time.

Bolster Your Advanced Endpoint Protection (AEP)

Download the Digital Defense white paper here.

While dwell times have slightly decreased as attackers become less patient, they are still significant enough to evade the plethora of security tools that exist today. The challenge with these tools is their inability to piece together attacker activity over long periods. By the time enough indicators of compromise (IoC) reveal themselves to be detected, it is often too late to prevent a breach. Most monitoring solutions look for attacker activity to identify a potential indicator of compromise. However, the best way to combat dwell time is to identify and eradicate dormant or nascent malware that stays well-hidden before they periodically activate.

A layered solution

Frontline Active Threat Sweep™ (Frontline ATS™), integrated with Microsoft Defender for Endpoint, identifies malware designed to actively evade EDR solutions. Frontline ATS™ is part of the Digital Defense Frontline.Cloud platform providing on-demand agentless threat detection that proactively analyzes assets for indications of a malware infection before other agent-based security tools can be deployed. When integrated, Frontline ATS augments Defender for Endpoint’s capabilities by identifying hidden IoCs without adding agents.

The ability to stay undetected for long periods of time is one of the most common and challenging tactics that attackers use to execute a successful breach. In addition, even when a security team using monitoring tools or an incident response (IR) service is able to detect a threat and clean up an infection, it is common to see it repeatedly resurface. This is because even though all active indicators of the threat have been investigated and addressed, if the initial, and often inactive, installation of malware is not discovered due to inactivity, it can later be re-activated to re-spark an infection. With Frontline ATS and Defender for Endpoint, security teams can find any source, artifact, or inactive remnants of malware that could restart the attack campaign. Defender for Endpoint and Frontline ATS provides comprehensive and unobtrusive advanced endpoint detection, protection, and response for drastically improving the security operations team’s effectiveness at preventing breaches.

To learn about the Digital Defense Frontline ATS integration with Microsoft Defender for Endpoint, please visit our listing in the Microsoft Azure Marketplace or visit Digital Defense to learn more.

To learn more about the Microsoft Intelligent Security Association (MISA), visit our website where you can learn about the MISA program, product integrations, and find MISA members. Visit the video playlist to learn about the strength of member integrations with Microsoft products.

For more information about Microsoft Security Solutions, visit the Microsoft Security website. Bookmark the Security blog to keep up with our expert coverage of security matters. Also, follow us at @MSFTSecurity for the latest news and updates on cybersecurity.

The post Digital Defense integrates with Microsoft to detect attacks missed by traditional endpoint security appeared first on Microsoft Security Blog.