On Thursday 3 March 2022 at 13:58 UTC, a HTTP GET flood targeted a municipal services customer in Central Europe. The attack peaked at 479.5 million requests per second and lasted 39 minutes. Traffic originated from 1735 autonomous systems in 35 countries, predominantly hijacked home routers.
| Vector | HTTP GET flood |
| Peak | 479.5 million requests per second |
| Duration | 39 min |
| Time to mitigation | 0.914 s |
| Attack traffic reaching origin | 0.087% |
| Legitimate traffic challenged | 0.05% |
Timeline
The attack was preceded by a ransom note demanding payment in Monero. Request rates on the targeted routes exceeded their hourly baseline by a factor of 223 within 17 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.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable authenticated origin pulls.