The Largest DDoS Attack in History: Cloudflare Fights Back

Earlier this year, in mid-May, Cloudflare announced that it had successfully mitigated a record-breaking 7.3 Tbps distributed denial-of-service attack. Now, only months later, the company has revealed a new milestone: a massive assault peaking at 11.5 Tbps and 5.1 billion packets per second, the largest such event ever recorded.

This latest strike was primarily driven by a UDP flood originating from Google Cloud infrastructure, and it came with the history of multi-vector campaigns that included UDP floods, NTP reflection attacks, and Mirai botnet payloads. Thanks to Cloudflare’s globally distributed network and automated defence mechanisms, its services suffered no noticeable disruption. Cloudflare had previously set a benchmark by thwarting the 7.3 Tbps attack, which lasted about 45 seconds and involved around 37.4 terabytes of traffic.

The evolution of these attacks underscores the need for resilient, automated detection and distribution of resources to defend against ever larger DDoS campaigns.