Aisuru Botnet Unleashes Record-Breaking 15.72 Tbps DDoS Attack on Microsoft Azure

A massive denial-of-service (DoS) attack hit Microsoft Azure on October 24, 2025, but the company's defense systems held strong. The attack, which was traced to the Aisuru botnet, reached a record-breaking scale of 15.72 terabit-per-second (Tbps) and nearly 3.64 billion packets per second (pps).

Azure Security senior product marketing manager Sean Whalen described the scale of the attack in Microsoft's blog post, saying: 'On October 24, 2025, Azure DDOS Protection automatically detected and mitigated a multi-vector DDoS attack measuring 15.72 Tbps and nearly 3.64 billion packets per second (pps). This was the largest DDoS attack ever observed in the cloud.'

The Aisuru botnet is a Mirai-derived IoT malware strain known for pushing attacks to extreme scales. According to Microsoft, its worldwide network of scrubbing centers absorbed and cleaned the malicious flow in real time, keeping Azure workloads online throughout the event.

Experts warn that as home internet speeds get faster and more smart devices fill our homes, the potential for even larger attacks continues to grow. Whalen noted: 'Attackers are scaling with the internet itself.'