{"id":90305,"date":"2019-12-12T09:00:10","date_gmt":"2019-12-12T17:00:10","guid":{"rendered":"https:\/\/www.microsoft.com\/en-us\/security\/blog\/\/?p=90305"},"modified":"2023-05-26T14:11:10","modified_gmt":"2023-05-26T21:11:10","slug":"gallium-targeting-global-telecom","status":"publish","type":"post","link":"https:\/\/www.microsoft.com\/en-us\/security\/blog\/2019\/12\/12\/gallium-targeting-global-telecom\/","title":{"rendered":"GALLIUM: Targeting global telecom"},"content":{"rendered":"

Microsoft Threat Intelligence Center (MSTIC) is raising awareness of the ongoing activity by a group we call GALLIUM, targeting telecommunication providers. When Microsoft customers have been targeted by this activity, we notified them directly with the relevant information they need to protect themselves. By sharing the detailed methodology and indicators related to GALLIUM activity, we\u2019re encouraging the security community to implement active defenses to secure the broader ecosystem from these attacks.<\/p>\n

To compromise targeted networks, GALLIUM target unpatched internet-facing services using publicly available exploits and have been known to target vulnerabilities in WildFly\/JBoss. Once persistence is established in a network, GALLIUM uses common techniques and tools like Mimikatz to obtain credentials that allows for lateral movement across the target network. Within compromised networks, GALLIUM makes no attempt to obfuscate their intent and are known to use common versions of malware and publicly available toolkits with small modifications. The operators rely on low cost and easy to replace infrastructure that consists of dynamic-DNS domains and regularly reused hop points.<\/p>\n

This activity from GALLIUM has been identified predominantly through 2018 to mid-2019. GALLIUM is still active; however, activity levels have dropped when compared to what was previously observed.<\/p>\n

Following Microsoft\u2019s internal practices of assigning chemical elements to activity groups, GALLIUM is the code name for this activity group.<\/p>\n

GALLIUM\u2019s profile<\/h3>\n

Reconnaissance methods<\/strong><\/p>\n

As is often the case with the reconnaissance methods, it\u2019s difficult to be definitive about those employed by GALLIUM. This is due to the passive nature of reconnaissance activities by the actor including the use of freely available data from open sources, such as public websites and social media outlets. However, based on MSTIC analyst assessments, GALLIUM\u2019s exploitation of internet-facing services indicates it\u2019s likely they use open source research and network scanning tools to identify likely targets.<\/p>\n

Delivery and exploitation<\/h3>\n

To gain initial access a target network, GALLIUM locates and exploits internet-facing services such as web servers. GALLIUM has been observed exploiting unpatched web services, such as WildFly\/JBoss, for which exploits are widely available. Compromising a web server gives GALLIUM a foothold in the victim network that doesn\u2019t require user interaction, such as traditional delivery methods like phishing.<\/p>\n

Following exploitation of the web servers, GALLIUM actors typically install web shells<\/a>, and then install additional tooling to allow them to explore the target network.<\/p>\n

Lateral movement<\/strong><\/p>\n

GALLIUM uses a variety of tools to perform reconnaissance and move laterally within a target network. The majority of these are off-the-shelf tools or modified versions of known security tools. MSTIC investigations indicate that GALLIUM modifies its tooling to the extent it evades antimalware detections rather than develop custom functionality. This behavior has been observed with GALLIUM actors across several operational areas.<\/p>\n

GALLIUM has been observed using several tools. Samples of the most prevalent are noted in Table 1.<\/p>\n\n\n\n\n\n\n\n\n\n\n
Tool<\/strong><\/td>\nPurpose<\/strong><\/td>\n<\/tr>\n
HTRAN<\/a><\/td>\nConnection bouncer to proxy connections.<\/td>\n<\/tr>\n
Mimikatz<\/a><\/td>\nCredential dumper.<\/td>\n<\/tr>\n
NBTScan<\/a><\/td>\nScanner for open NETBIOS nameservers on a local or remote TCP\/IP network.<\/td>\n<\/tr>\n
Netcat<\/td>\nReads from and writes to network connections using TCP or UDP protocols.<\/td>\n<\/tr>\n
PsExec<\/a><\/td>\nExecutes a command line process on a remote machine.<\/td>\n<\/tr>\n
Windows Credential Editor (WCE)<\/a><\/td>\nCredential dumper.<\/td>\n<\/tr>\n
WinRAR<\/td>\nArchiving utility.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Table <\/em>1<\/em>: GALLIUM tooling.<\/em><\/p>\n

GALLIUM has signed several tools using stolen code signing certificates. For example, they\u2019ve used a credential dumping tool signed using a stolen certificate from Whizzimo, LLC<\/em>, as shown in Figure 1. The code signing certificate shown in Figure 1 was no longer valid at the time of writing; however, it shows GALLIUM had access to such certificates.<\/p>\n

\"Image<\/p>\n

Figure 1. Credential dumping tool signed using a stolen Whizzimo, LLC certificate.<\/em><\/p>\n

GALLIUM primarily relies on compromised domain credentials to move through the target network, and as outlined above, uses several credential harvesting tools. Once they have acquired credentials, the activity group uses PsExec extensively to move laterally between hosts in the target network.<\/p>\n

Installation<\/strong><\/p>\n

GALLIUM predominantly uses widely available tools. In certain instances, GALLIUM has modified these tools to add additional functionality. However, it\u2019s likely these modifications have been made to subvert antimalware solutions since much of the malware and tooling employed by GALLIUM is historic and is widely detected by security products. For example, QuarkBandit<\/a> is a modified version of the widely used Gh0st RAT, an openly available remote access tool (RAT). Similarly, GALLIUM has made use of a modified version of the widely available Poison Ivy RAT<\/a>. These RATs and the China Chopper web shell<\/a> form the basis of GALLIUM\u2019s toolkit for maintaining access to a victim network.<\/p>\n

Infrastructure<\/strong><\/p>\n

GALLIUM predominantly uses dynamic DNS subdomains to provide command and control (C2) infrastructure for their malware. Typically, the group uses the ddns.net and myftp.biz domains provided by noip.com. MSTIC analysis indicates the use of dynamic DNS providers as opposed to registered domains is in line with GALLIUM\u2019s trend towards low cost and low effort operations.<\/p>\n

GALLIUM domains have been observed hosted on infrastructure in mainland China, Hong Kong SAR, and Taiwan.<\/p>\n

When connecting to web shells on a target network GALLIUM has been observed employing Taiwan-based servers. Observed IP addresses appear to be exclusive to GALLIUM, have little to no legitimate activity, and are reused in multiple operations. These servers provide high fidelity pivot points during an investigation.<\/p>\n

A package of GALLIUM indicators containing GALLIUM command and control domains used during this operation have been prepared for Azure Sentinel<\/a> and is available on the Microsoft GitHub<\/a>.<\/p>\n

\"Image<\/p>\n

Figure <\/em>2.<\/em> Azure Sentinel query of GALLIUM indicators.<\/em><\/p>\n

GALLIUM use of malware<\/h3>\n

First stage <\/strong><\/p>\n

GALLIUM does not typically use a traditional first stage installer for their malware. Instead, the group relies heavily on web shells as a first method of persistence in a victim network following successful exploitation. Subsequent malware is then delivered through existing web shell access.<\/p>\n

Microsoft Defender Advanced Threat Protection (ATP) exposes anomalous behavior that indicate web shell installation and post compromise activity by analysing script file writes and process executions. Microsoft Defender ATP<\/a> offers a number of detections for web shell activity protecting customers not just from GALLIUM activity but broader web shell activity too. Read the full report in your Microsoft Defender ATP portal<\/a>.<\/p>\n

\"Image<\/p>\n

Figure 3. <\/em>Microsoft Defender ATP web shell detection.<\/em><\/p>\n

When alerted of these activities, the security operations team can then use the rich capabilities in Microsoft Defender ATP to investigate web shell activity and subsequent reconnaissance and enumeration activity to resolve web shell attacks.<\/p>\n

\"Image<\/p>\n

Figure 4. Microsoft Defender ATP web shell process tree.<\/em><\/p>\n

In addition to standard China Chopper<\/a>, GALLIUM has been observed using a native web shell for servers running Microsoft IIS that is based on the China Chopper web shell; Microsoft has called this \u201cBlackMould.\u201d<\/p>\n

BlackMould contains functionality to perform the following tasks on a victim host:<\/p>\n