Massive DDoS Attack Used 1.2 Million IPs to Bypass Rate Limits

A sophisticated, large-scale volumetric DDoS campaign produced 2.45 billion requests across five hours (peaking >200,000 rps) against a major user-generated content platform, distributing traffic across 1.2 million IPs and 16,000+ ASNs and using wave-based pacing and IP/user-agent rotation to defeat threshold-based defenses; defenders mitigated the attack by applying behavioral baselines and session-level fingerprinting, achieving complete mitigation with no impact to legitimate users.