On Wednesday 15 November 2023 at 03:16 UTC, a cache-busting query flood targeted a municipal services customer in the Middle East. The attack peaked at 394.8 million requests per second and lasted 137 minutes. Traffic originated from 3134 autonomous systems in 93 countries, predominantly mobile carrier ranges.
| Vector | cache-busting query flood |
| Peak | 394.8 million requests per second |
| Duration | 137 min |
| Time to mitigation | 0.141 s |
| Attack traffic reaching origin | 0.027% |
| Legitimate traffic challenged | 0.67% |
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 709 within 21 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 log streaming to your SIEM for faster correlation.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Add a dedicated rate limit for the targeted route.
Is the risk score exposed in the logs so we can build our own dashboards on it?