Cloudflare, a company that protects websites from online attacks, said it stopped the largest cyber attack on record.
“Cloudflare’s defenses have been working overtime. Over the past few weeks, we’ve autonomously blocked hundreds of hyper-volumetric distributed denial-of-service (DDoS) attacks, with the largest reaching peaks of 5.1 Bpps and 11.5 Tbps,” Cloudflare wrote on X on Tuesday.
Cloudflare’s defenses have been working overtime. Over the past few weeks, we’ve autonomously blocked hundreds of hyper-volumetric DDoS attacks, with the largest reaching peaks of 5.1 Bpps and 11.5 Tbps. The 11.5 Tbps attack was a UDP flood that mainly came from Google Cloud.… pic.twitter.com/3rOys7cfGS
— Cloudflare (@Cloudflare) September 1, 2025
The assault consisted of a sudden wave of User Datagram Protocol (UDP) traffic. Cloudflare reported that much of the traffic originated from compromised Google Cloud resources.
The event surpassed Cloudflare’s previous record of 7.3 Tbps in May and 3.8 Tbps in October 2024.
Cloudflare said it blocked 27.8 million DDoS attempts in the first half of 2025, already exceeding the 21.3 million seen in all of 2024.
