On Thursday 18 January 2024 at 05:07 UTC, a HTTP POST flood targeted a education platform customer in the Benelux. The attack peaked at 555.7 million requests per second and lasted 185 minutes. Traffic originated from 2040 autonomous systems in 13 countries, predominantly a headless-browser farm.
| Vector | HTTP POST flood |
| Peak | 555.7 million requests per second |
| Duration | 185 min |
| Time to mitigation | 0.866 s |
| Attack traffic reaching origin | 0.074% |
| Legitimate traffic challenged | 0.33% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 272 within 23 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.
- Review allow-listed partner ranges quarterly.
- Add a dedicated rate limit for the targeted route.