Microsoft has successfully stopped what is believed to be the largest cloud-based DDoS attack ever recorded, the company confirmed on Tuesday. The assault occurred on October 24, 2025, targeting a single public endpoint in Australia, but Azure’s global filtering network kept services online throughout the event.
The attack, originating from the Aisuru botnet, a Turbo Mirai-class network of compromised routers and IoT devices, peaked at 15.72 Tbps and nearly 3.64 billion packets per second. Traffic was launched from over 500,000 IP addresses using massive UDP floods.
Security experts noted the attack highlights the rapid growth of DDoS capabilities as high-speed home networks and IoT devices provide attackers with more bandwidth and processing power.
With the holiday season approaching, a period when DDoS attacks often increase, Microsoft urged organizations to review defenses and ensure all internet-facing systems are protected against increasingly powerful attacks.
