On Monday 28 February 2022 at 19:15 UTC, a HTTP/2 rapid reset targeted a airline booking customer in Iberia. The attack peaked at 238.5 million requests per second and lasted 181 minutes. Traffic originated from 2588 autonomous systems in 31 countries, predominantly a Mirai-derived IoT botnet.
| Vector | HTTP/2 rapid reset |
| Peak | 238.5 million requests per second |
| Duration | 181 min |
| Time to mitigation | 0.572 s |
| Attack traffic reaching origin | 0.073% |
| Legitimate traffic challenged | 0.59% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 249 within 15 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
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.
- Enable log streaming to your SIEM for faster correlation.