On Wednesday 20 April 2022 at 01:42 UTC, a HTTP POST flood targeted a ticketing customer in the UK. The attack peaked at 213.5 million requests per second and lasted 65 minutes. Traffic originated from 1790 autonomous systems in 50 countries, predominantly misconfigured open reflectors.
| Vector | HTTP POST flood |
| Peak | 213.5 million requests per second |
| Duration | 65 min |
| Time to mitigation | 0.710 s |
| Attack traffic reaching origin | 0.018% |
| Legitimate traffic challenged | 0.08% |
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 535 within 33 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
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.