On Saturday 18 December 2021 at 06:37 UTC, a Slowloris targeted a online payments customer in Latin America. The attack peaked at 326.5 million requests per second and lasted 122 minutes. Traffic originated from 3344 autonomous systems in 68 countries, predominantly a Mirai-derived IoT botnet.
| Vector | Slowloris |
| Peak | 326.5 million requests per second |
| Duration | 122 min |
| Time to mitigation | 0.938 s |
| Attack traffic reaching origin | 0.039% |
| Legitimate traffic challenged | 0.63% |
Timeline
The attack was preceded by a hacktivist channel announcing the target. Request rates on the targeted routes exceeded their hourly baseline by a factor of 67 within 27 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
- Keep origin IPs out of public DNS history.
- Enable log streaming to your SIEM for faster correlation.
- Add a dedicated rate limit for the targeted route.