Threat Bulletin 0031: HTTP/2 rapid reset against a electronics retail platform in Latin America

On Sunday 11 April 2021 at 21:56 UTC, a HTTP/2 rapid reset targeted a electronics retail customer in Latin America. The attack peaked at 824.8 million requests per second and lasted 89 minutes. Traffic originated from 273 autonomous systems in 31 countries, predominantly hijacked home routers.

Timeline

The attack was preceded by a competitor’s product launch. Request rates on the targeted routes exceeded their hourly baseline by a factor of 436 within 13 seconds. The risk score of participating clients crossed the challenge threshold automatically and proof-of-work difficulty rose with origin load.

What the customer saw

The customer’s status page stayed green throughout; they learned about the attack from our notification.

Recommendations

• Review allow-listed partner ranges quarterly.
• Keep origin IPs out of public DNS history.
• Enable log streaming to your SIEM for faster correlation.