Record-Breaking DDoS Attack Hits 37.4 TB in Just 45 Seconds

In a dramatic spike of cyber aggression, Cloudflare has reported the largest Distributed Denial-of-Service (DDoS) attack ever seen. The scale was jaw-dropping: 37.4 terabytes of data flooded a single target in just 45 seconds. At its peak, traffic surged to 7.3 terabits per second (Tbps), setting a new global record.

To put it in perspective, that’s enough data to stream thousands of HD movies or transfer millions of files in less than a minute.

How the Attack Worked

The attack used multiple techniques, with the primary method being a UDP flood. Unlike TCP, the more common internet protocol, UDP sends data without needing a handshake or confirmation. This makes it faster, but also more vulnerable to abuse. UDP is often used in real-time applications like online gaming or video streaming. Unfortunately, it’s also perfect for DDoS.

Cloudflare also identified reflection and amplification attacks. In these cases, attackers spoof the target’s IP address and send requests to third-party servers. Those servers then unknowingly send large amounts of data back to the victim, overwhelming their systems.

DDoS: An Escalating Threat

This isn’t the first major DDoS event. In January 2022, Microsoft faced an attack reaching 3.47 Tbps. That record was broken in October 2024 with a 5.6 Tbps attack, and again in April 2025 with 6.5 Tbps over nearly 49 seconds. Now, this latest attack sets a new peak.

Most of these attacks are powered by botnets — vast networks of hijacked devices, often including everyday gadgets. They remain one of the most accessible and dangerous tools for cybercriminals today.