On Tuesday 18 March 2025 at 03:25 UTC, a TLS handshake exhaustion targeted a video streaming customer in the Middle East. The attack peaked at 68.1 million requests per second and lasted 10 minutes. Traffic originated from 1232 autonomous systems in 40 countries, predominantly misconfigured open reflectors.
| Vector | TLS handshake exhaustion |
| Peak | 68.1 million requests per second |
| Duration | 10 min |
| Time to mitigation | 0.318 s |
| Attack traffic reaching origin | 0.090% |
| Legitimate traffic challenged | 0.20% |
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 434 within 33 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 234 ms during the first minute, then normal service.
Recommendations
- Add a dedicated rate limit for the targeted route.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.