Cloudflare claimed to have recently mitigated the largest distributed denial of service (DDoS) attack in history.
In a company blog post, Cloudflare described how, throughout September 2024, an anonymous threat actor targeted multiple customers in the financial services, Internet, and telecommunications industries, among others.
Without naming any specific targets, Cloudflare said the attack campaign aimed at bandwidth saturation as well as resource depletion of online applications and devices.
Bots around the world
The attack included “more than one hundred L3/4 hypervolumetric DDoS attacks,” many of which exceeded 2 billion packets per second (Bpps) and 3 terabits per second (Tbps).
A hypervolumetric L3/4 DDoS attack is a type of DDoS attack that targets layers 3 (network) and 4 (transport) of the OSI model (a framework that standardizes network communication). Overwhelms the target's bandwidth or network infrastructure with massive amounts of traffic, often using techniques such as UDP flooding or TCP SYN flooding. The goal is to exhaust the resources of the target system, making it unavailable to legitimate users.
Of all the attacks, one stood out: it peaked at 3.8 Tbps. This is, according to Cloudflare, “the largest ever publicly disclosed by any organization.” It predominantly leveraged UDP on a fixed port, the company said, and originated around the world. Most of the endpoints used in the attack came from Vietnam, Russia, Brazil, Spain and the United States.
Detection and mitigation were fully automated, Cloudflare says. He added that the key reason he was able to address it was because the company has servers around the world, which essentially dilute incoming botnet traffic.
Typically, DDoS attacks are carried out through botnets: vast networks of compromised endpoints, such as routers, smart home devices, and the like. These attacks included traffic from MikroTik devices, DVRs, and web servers, as well as compromised ASUS home routers, which were likely exploited using a CVE 9.8 (critical) vulnerability recently discovered by Censys.
Prior to this, the largest DDoS attack ever observed was 3.47 Tbps and was mitigated by Microsoft in November 2021.
Through PCMag