Record-Shattering DDoS Attack Targets Microsoft Azure
SEATTLE, WA – A massive distributed denial-of-service (DDoS) attack, peaking at a staggering 2.4 terabits per second, recently targeted Microsoft Azure, marking the largest cloud DDoS attack ever recorded. The assault, mitigated by Microsoft’s Azure DDoS Protection service, lasted approximately 10 minutes and originated from a botnet known as Aisuru.
This unprecedented attack underscores the escalating threat landscape facing cloud infrastructure providers and their customers. While Aisuru’s operators claim too avoid targeting critical national infrastructure, security experts remain skeptical given the group’s demonstrated capacity for disruption. The incident highlights the critical need for robust DDoS mitigation strategies as attackers increasingly leverage larger and more sophisticated botnets to overwhelm online services.
The Aisuru botnet, comprised of compromised devices, flooded Azure with a torrent of requests. Microsoft reported the attack utilized a combination of volumetric and protocol attacks, attempting to exhaust network bandwidth and overwhelm Azure’s systems. “The attacker is just generating a ton of requests, maybe to influence the ranking but also to attack our DNS service,” explained Cloudflare CEO Matthew Prince, who observed similar activity impacting their services. Cloudflare recently removed domains linked to Aisuru from it’s Top Domains ranking after thay briefly surpassed major websites like Amazon, Apple, Google, and Microsoft in traffic volume.
According to security researcher Ben Whalen, attackers are continually scaling their capabilities alongside the growth of the internet itself. This latest incident follows a broader trend of increasing DDoS attacks; Cloudflare’s Q2 2025 DDoS Threat Report documented a more than 40 percent surge in attacks compared to the same period last year. While Microsoft successfully mitigated the attack, the sheer scale serves as a warning of potential future disruptions and the ongoing arms race between attackers and defenders.
