On Monday 6 December 2021 at 06:57 UTC, a TLS handshake exhaustion targeted a sports betting customer in Southeast Asia. The attack peaked at 679.6 million requests per second and lasted 98 minutes. Traffic originated from 4113 autonomous systems in 8 countries, predominantly hijacked home routers.
| Vector | TLS handshake exhaustion |
| Peak | 679.6 million requests per second |
| Duration | 98 min |
| Time to mitigation | 0.803 s |
| Attack traffic reaching origin | 0.084% |
| Legitimate traffic challenged | 0.69% |
Timeline
The attack was preceded by a publicly announced sales event. Request rates on the targeted routes exceeded their hourly baseline by a factor of 742 within 36 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
- Enable log streaming to your SIEM for faster correlation.
- Keep origin IPs out of public DNS history.
- Add a dedicated rate limit for the targeted route.