A deep dive into investigating a complex denial of service attack

On April 19, 2024, Datadog’s US5 website experienced low-level error rates due to a meticulously crafted DoS attack. The attack exploited a GCP load balancer vulnerability, causing malformed requests to overload the system. By April 26, 2024, the issue was fully mitigated through a combination of traffic redirection and custom Cloud Armor rules.