While distributed denial-of-service (DDoS) attacks happen all year round, the holiday season is when some of the most high-profile attacks occur. Here’s your guide for keeping safe.

A DDoS overview

DDoS attacks are carried out by individual devices (bots) or network of devices (botnet) that have been infected with malware and used to flood websites or services with high volumes of traffic. DDoS attacks can last a few hours, or even days.

What: A DDoS attack floods a site or server with errant traffic to disrupt service or knock it offline.

Why: Criminals use DDoS attacks to extort site owners for financial, competitive advantage, or political reasons.

How: Thanks to the cybercrime-as-a-service business model, a DDoS attack can be ordered from a DDoS subscription service for as little as $5.¹

3 reasons why DDoS attacks are so common during the holidays

One: Organizations typically have reduced resources dedicated to monitoring their networks and applications—providing easier opportunities for threat actors to execute an attack.

Two: Traffic volume is at an all-time high (this year, sales are expected to reach $1.33 trillion), especially for e-commerce websites and gaming providers, making it harder for IT staff to distinguish between legitimate and illegitimate traffic.

Three: For attackers seeking financial gain, the opportunity for more lucrative payouts can be higher during the holidays as revenues are at the highest and service uptime is critical.

Last year we highlighted how the holiday season saw an uptick in such attacks, underscoring the need for robust defenses.

The peril of holiday-season attacks

Any website or server downtime during the peak holiday season can result in lost sales and customers, high recovery costs, or damage to your reputation. The impact is even more significant for smaller organizations as it can be harder for them to recover after an attack.

DDoS attack categories

In general, a DDoS attack falls under three primary categories, with a variety of different cyberattacks within each category. New DDoS attack vectors emerge every day as cybercriminals leverage more advanced techniques, such as AI-based attacks. Attackers can use multiple attack types, including ones from different categories, against a network.

Volumetric attacks: Targets bandwidth. They are designed to overwhelm the network layer with traffic.

Example: A DNS (domain name server) amplification attack, which uses open DNS servers to flood a target with DNS response traffic

Protocol attacks: Targets resources. They exploit weaknesses in the layer 3 and layer 4 protocol stack.

Example: A SYN (synchronization packet flood) attack, which consumes all available server resources (thus making a server unavailable).

Resource layer attacks: Targets web application packets. They disrupt the transmission of data between hosts.

Example: An HTTP/2 Rapid Reset attack, which sends a set number of HTTP requests using HEADERS followed by RST_STREAM and repeating this pattern to generate a high volume of traffic on the targeted HTTP/2 servers.

Tips for helping protect and respond against DDoS attacks

While you cannot completely avoid being a target of a DDoS attack, proactive planning and preparation can help you establish a more effective defense.

That said, it’s important to remember how higher levels of traffic around the holidays may make abnormalities harder to detect.

1. Evaluate your risks and vulnerabilities: Start by identifying the applications within your organization that are exposed to the public internet. Also, be sure to note the normal behavior of your application so you can respond quickly if it begins behaving differently than expected.

2. Make sure you’re protected: With DDoS attacks at an all-time high during the holidays, you need a DDoS protection service with advanced mitigation capabilities that can handle attacks at any scale. Look for service features such as traffic monitoring; protection tailored to the specifics of your application; DDoS protection telemetry, monitoring, and alerting; and access to a rapid response team.

3. Create a DDoS response strategy: Having a response strategy is critical to help you identify, mitigate, and quickly recover from DDoS attacks. A key part of the strategy involves assembling a DDoS response team with clearly defined roles and responsibilities. This DDoS response team should understand how to identify, mitigate, and monitor an attack and be able to coordinate with internal stakeholders and customers.

4. Reach out for help during an attack: If you think you are experiencing an attack, reach out to the appropriate technical professionals, such as an established DDoS response team, for help with attack investigation during an attack as well as post-attack analysis once it has concluded.

5. Learn and adapt after an attack: While you’ll likely want to move on as quickly as possible if you’ve experienced an attack, it’s important to continue to monitor your resources and conduct a retrospective after an attack. Make sure your post-attack analysis considers the following:

• Was there any disruption to the service or user experience due to a lack of scalable architecture?
• Which applications or services suffered the most?
• How effective was the DDoS response strategy, and how can it be improved?

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