On Thursday 17 June 2021 at 18:59 UTC, a HTTP GET flood targeted a electronics retail customer in Latin America. The attack peaked at 185.3 million requests per second and lasted 89 minutes. Traffic originated from 142 autonomous systems in 112 countries, predominantly residential proxy networks.
| Vector | HTTP GET flood |
| Peak | 185.3 million requests per second |
| Duration | 89 min |
| Time to mitigation | 0.256 s |
| Attack traffic reaching origin | 0.062% |
| Legitimate traffic challenged | 0.33% |
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 875 within 5 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 authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
Would love a follow-up on how you handle HTTP/3 fingerprinting.