On Friday 13 May 2022 at 05:34 UTC, a HTTP GET flood targeted a crypto exchange customer in the Nordics. The attack peaked at 256.8 million requests per second and lasted 76 minutes. Traffic originated from 2143 autonomous systems in 77 countries, predominantly misconfigured open reflectors.
| Vector | HTTP GET flood |
| Peak | 256.8 million requests per second |
| Duration | 76 min |
| Time to mitigation | 0.660 s |
| Attack traffic reaching origin | 0.054% |
| Legitimate traffic challenged | 0.70% |
Timeline
The attack was preceded by a competitor’s product launch. Request rates on the targeted routes exceeded their hourly baseline by a factor of 756 within 13 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 80 ms during the first minute, then normal service.
Recommendations
- Enable authenticated origin pulls.
- Keep origin IPs out of public DNS history.
- Lower challenge thresholds on authentication endpoints during high-risk events.