Azure Mitigates Record 15.72 Tbps Cloud DDoS Attack

Microsoft Azure successfully mitigated the largest distributed denial-of-service (DDoS) attack ever recorded in the cloud on October 24, 2025, when cybercriminals launched a massive assault from the Aisuru botnet against a single endpoint in Australia.

The attack peaked at 15.72 terabits per second (Tbps) and nearly 3.64 billion packets per second, originating from more than 500,000 source IP addresses worldwide. It involved multi-vector tactics, primarily high-rate User Datagram Protocol (UDP) floods with minimal source spoofing and random source ports, which targeted a specific public IP address. According to Sean Whalen, senior product marketing manager for Azure Security, the incident marked "the largest DDoS attack ever observed in the cloud." The botnet, comprising hundreds of thousands of compromised Internet of Things (IoT) devices such as consumer routers, CCTV systems, and digital video recorders, drew most of its nodes from residential internet service providers in the United States and other regions.

Azure's globally distributed DDoS Protection infrastructure detected the assault automatically and filtered the malicious traffic, redirecting it to prevent any...