321/68 Thursday, September 4, 2025
Cloudflare has revealed that it successfully mitigated the largest DDoS (Distributed Denial of Service) attack ever recorded, which peaked at 11.5 terabits per second (Tbps). The attack, primarily a UDP flood originating mostly from Google Cloud, was part of a prolonged campaign spanning several weeks. In addition, Cloudflare blocked hundreds of other massive DDoS attacks during the same period—representing a 12% increase over the previous largest known attack.
Previously, in Q2 2025, Cloudflare announced that it had also mitigated record-breaking DDoS attacks that peaked at 7.3 Tbps and 4.8 billion packets per second (pps). That attack managed to deliver 37.4 terabytes of traffic within just 45 seconds—equivalent to streaming over 9,350 HD movies or downloading more than 9.35 million songs in under a minute.
The earlier campaign was multi-vector in nature, with the vast majority of traffic being UDP floods, alongside other protocols such as QOTD, Echo, NTP, Mirai, Portmap, and RIPv1. These incidents underscore the growing scale, speed, and sophistication of modern cyberattacks and highlight the need for robust global defenses against DDoS campaigns.
