Loop DDoS Attacks: Understanding the Threat and Azure's Defense

This article provides a comprehensive overview of Loop DDoS attacks, a sophisticated and evolving cybersecurity threat that exploits application-layer protocols relying on User Datagram Protocol (UDP). While Microsoft has not witnessed a Loop attack translated into an actual DDoS attack yet, the possibility is real given the recent trends and attack vectors of DDoS attacks. Specifically, Loop DDoS attacks impact applications in two ways:

• The endless loop of error messages from one application server to another that may overwhelm the CPU and render it unavailable to serve legitimate client requests
• The potential volumetric nature of the attack that can saturate networks and network connections

Thus, the author goes on to describe Microsoft’s approach to DDoS attacks, utilizing multiple layers of DDoS protection across its network topology to safeguard its platform against volumetric floods regardless of whether it’s an application attack presenting itself as a network flood or a volumetric TCP or UDP attack. Moreover, there are different countermeasures employed to protect against web attacks, DNS attacks, and attacks on gaming workloads. The author recommends all customers with resources that are reachable from the internet to onboard to Azure's DDoS protection offering, to ensure that their resources are protected against volumetric attacks, including Loop attacks.