In an impressive display of technological prowess, Cloudflare has successfully thwarted the largest volumetric distributed denial-of-service (DDoS) attack ever recorded, peaking at an astounding 11.5 terabits per second (Tbps). This monumental attack was automatically neutralized by Cloudflare’s advanced security measures, showcasing their commitment to keeping the internet safe.
According to a recent tweet from Cloudflare, their defenses have been working tirelessly. Just in the past few weeks, they have autonomously blocked hundreds of hyper-volumetric DDoS attacks. The largest of these, reaching peaks of 5.1 Bbps and 11.5 Tbps, was identified as a UDP flood, primarily originating from Google Cloud servers. Remarkably, this massive assault lasted only about 35 seconds, yet its scale marked it as one of the most significant events in internet history.
This record-setting attack comes merely two months after Cloudflare successfully mitigated a 7.3 Tbps DDoS attack in June. Prior to that, the highest recorded attack stood at 3.8 Tbps in October 2024. Other tech giants like Microsoft have not been immune to such threats, with a notable incident in January 2022 involving a 3.47 Tbps attack targeting an Azure customer, followed by another disruption impacting multiple Microsoft 365 and Azure services in July 2024.
Cloudflare’s report for Q1 2025 reveals a staggering 358% year-over-year increase in DDoS attacks, with over 21 million incidents mitigated in 2024 alone. Many of these attacks have been complex, utilizing multi-vector strategies, including SYN floods, SSDP amplification, and Mirai-based botnets.
Understanding DDoS attacks is crucial—they aim to overwhelm servers or networks with an avalanche of data, rendering them inaccessible to legitimate users. The alarming growth in the scale of these attacks emphasizes how attackers are increasingly leveraging cloud resources and botnets to amplify their malicious campaigns. As technology evolves, so too must our defenses, and Cloudflare’s latest achievement is a shining example of resilience in the face of adversity.
