On Tuesday 24 May 2022 at 08:06 UTC, a HTTP POST flood targeted a municipal services customer in Western Europe. The attack peaked at 146.5 million requests per second and lasted 82 minutes. Traffic originated from 1062 autonomous systems in 88 countries, predominantly a rented booter service.
| Vector | HTTP POST flood |
| Peak | 146.5 million requests per second |
| Duration | 82 min |
| Time to mitigation | 0.479 s |
| Attack traffic reaching origin | 0.006% |
| Legitimate traffic challenged | 0.72% |
Timeline
The attack was preceded by a publicly announced sales event. Request rates on the targeted routes exceeded their hourly baseline by a factor of 605 within 39 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
No customer-visible impact. The on-call engineer was notified and acknowledged the incident from the dashboard.
Recommendations
- Enable log streaming to your SIEM for faster correlation.
- Add a dedicated rate limit for the targeted route.
- Review allow-listed partner ranges quarterly.
This matches what we see in iGaming around big matches.
Great write-up. We saw almost the same pattern on our login endpoint last month.
Thanks! Yes — the risk score and its components are included in every log record.
How do you avoid challenging uptime monitors and partners?
Verified good bots and allow-listed partners bypass challenges entirely.
Carpet bombing is nasty. Good to see a clear explanation of it.
Would love a follow-up on how you handle HTTP/3 fingerprinting.