On Saturday 12 March 2022 at 03:20 UTC, a HTTP/2 rapid reset targeted a municipal services customer in Iberia. The attack peaked at 82.0 million requests per second and lasted 123 minutes. Traffic originated from 1986 autonomous systems in 10 countries, predominantly mobile carrier ranges.
| Vector | HTTP/2 rapid reset |
| Peak | 82.0 million requests per second |
| Duration | 123 min |
| Time to mitigation | 0.641 s |
| Attack traffic reaching origin | 0.036% |
| Legitimate traffic challenged | 0.73% |
Timeline
The attack was preceded by an extortion email received two days earlier. Request rates on the targeted routes exceeded their hourly baseline by a factor of 103 within 8 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
- Enable authenticated origin pulls.
- Review allow-listed partner ranges quarterly.
- Keep origin IPs out of public DNS history.