Microsoft this week reported that it recently mitigated a record-breaking distributed denial-of-service (DDoS) attack aimed at its Azure cloud service.
The tech giant said it was the “largest DDoS attack ever observed in the cloud”, peaking at 15.72 terabits per second (Tbps) and nearly 3.64 billion packets per second (Bpps).
However, Microsoft confirmed to SecurityWeek that the figure referred to the largest attack ever recorded targeting Azure, and not the largest DDoS attack recorded globally.
The largest publicly reported DDoS attack to date was aimed at a European network infrastructure company, and it peaked at 22.2 Tbps and 10.6 Bpps, according to Cloudflare. The attack was powered by the Aisuru botnet.
The attack on Azure was conducted on October 24 and it targeted a single endpoint in Australia. Similar to the 22 Tbps attack observed by Cloudflare, the Azure attack was powered by Aisuru.
“The attack involved extremely high-rate UDP floods targeting a specific public IP address, launched from over 500,000 source IPs across various regions,” explained Microsoft’s Sean Whalen. “These sudden UDP bursts had minimal source spoofing and used random source ports, which helped simplify traceback and facilitated provider enforcement.”
Aisuru has been described as a TurboMirai-class IoT botnet powered by compromised consumer-grade devices such as routers, CCTV cameras, and DVR systems.
Aisuru, offered as a DDoS-for-hire service, has been responsible for large DDoS attacks, particularly ones aimed at online gaming platforms. The botnet can also be used for credential stuffing, web scraping, phishing, and spamming.
Netscout reported recently that TurboMirai-class botnets “cannot generate spoofed DDoS attack traffic, allowing traceback and correlation with subscriber information that can be utilized to identify, quarantine, and remediate compromised devices”.
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