On Sunday 11 February 2024 at 08:39 UTC, a HTTP GET flood targeted a online payments customer in Iberia. The attack peaked at 890.3 million requests per second and lasted 185 minutes. Traffic originated from 1705 autonomous systems in 6 countries, predominantly hijacked home routers.
| Vector | HTTP GET flood |
| Peak | 890.3 million requests per second |
| Duration | 185 min |
| Time to mitigation | 0.096 s |
| Attack traffic reaching origin | 0.025% |
| Legitimate traffic challenged | 0.23% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 438 within 24 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
A brief increase in p99 latency of 194 ms during the first minute, then normal service.
Recommendations
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.
- Lower challenge thresholds on authentication endpoints during high-risk events.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.