On Saturday 22 April 2023 at 02:44 UTC, a Slowloris targeted a news publisher customer in Central Europe. The attack peaked at 427.2 million requests per second and lasted 32 minutes. Traffic originated from 776 autonomous systems in 48 countries, predominantly hijacked home routers.
| Vector | Slowloris |
| Peak | 427.2 million requests per second |
| Duration | 32 min |
| Time to mitigation | 0.639 s |
| Attack traffic reaching origin | 0.056% |
| Legitimate traffic challenged | 0.29% |
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 543 within 34 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 183 ms during the first minute, then normal service.
Recommendations
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.
- Lower challenge thresholds on authentication endpoints during high-risk events.