On Tuesday 26 September 2023 at 21:46 UTC, a HTTP GET flood targeted a news publisher customer in Iberia. The attack peaked at 318.2 million requests per second and lasted 21 minutes. Traffic originated from 528 autonomous systems in 50 countries, predominantly misconfigured open reflectors.
| Vector | HTTP GET flood |
| Peak | 318.2 million requests per second |
| Duration | 21 min |
| Time to mitigation | 0.226 s |
| Attack traffic reaching origin | 0.007% |
| Legitimate traffic challenged | 0.13% |
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 351 within 29 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
- Add a dedicated rate limit for the targeted route.
- Enable log streaming to your SIEM for faster correlation.
- Enable authenticated origin pulls.