The digital world was rocked recently by a distributed denial-of-service (DDoS) attack of unprecedented scale, with a staggering 7.3 terabits per second (Tbps) of malicious traffic pummeling an unnamed hosting provider. This “carpet bombing” of junk data, which delivered a colossal 37.4 terabytes in just 45 seconds, marks a new, alarming benchmark in cyber warfare.
The monumental assault, mitigated by internet security giant Cloudflare in mid-May, targeted a Cloudflare customer that relies on its “Magic Transit” service for network defense. To put the sheer volume into perspective, 37.4 terabytes is equivalent to downloading over 9,350 full-length HD movies or streaming 7,480 hours of high-definition video in under a minute – a once-unimaginable barrage of data designed to overwhelm and disrupt services.
The attack was a sophisticated, multi-vector assault, though an overwhelming 99.996% of the malicious traffic consisted of UDP floods. These floods attempt to saturate a target’s internet link with more packets than it can possibly handle. The remaining, albeit smaller, fraction of the attack utilized various reflection and amplification techniques, including QOTD, Echo, NTP, Mirai UDP floods, Portmap, and RIPv1 amplification. These methods exploit legitimate but often outdated internet protocols to amplify the attack’s impact.
The malicious traffic originated from a vast, globally distributed botnet, comprising over 122,145 unique IP addresses spanning 5,433 autonomous systems across 161 countries. Nearly half of the attack traffic was traced back to Brazil and Vietnam, with significant contributions also coming from Taiwan, China, Indonesia, Ukraine, Ecuador, Thailand, the United States, and Saudi Arabia.
Cloudflare’s global anycast network played a crucial role in mitigating the attack. By routing the malicious traffic to the nearest of its 477 data centers across 293 locations worldwide, Cloudflare effectively distributed the load, using the distributed nature of the attack against itself. The company’s autonomous DDoS mitigation system, employing real-time fingerprinting and advanced heuristics, swiftly identified attack patterns and dropped malicious packets without human intervention, ensuring legitimate traffic continued to flow.
This record-breaking DDoS event underscores the escalating scale and sophistication of cyber threats targeting critical internet infrastructure. As attackers increasingly harness larger botnets and exploit vulnerabilities in legacy protocols, the need for robust, automated, and globally distributed defense mechanisms becomes more critical than ever. The incident serves as a stark reminder that even the most well-protected entities are not immune to these increasingly powerful and relentless assaults.
