On Wednesday 29 October 2025 at 16:53 UTC, a TLS handshake exhaustion targeted a healthcare portal customer in the Middle East. The attack peaked at 155.1 million requests per second and lasted 87 minutes. Traffic originated from 271 autonomous systems in 8 countries, predominantly a Mirai-derived IoT botnet.
| Vector | TLS handshake exhaustion |
| Peak | 155.1 million requests per second |
| Duration | 87 min |
| Time to mitigation | 0.207 s |
| Attack traffic reaching origin | 0.041% |
| Legitimate traffic challenged | 0.75% |
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 549 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
A brief increase in p99 latency of 183 ms during the first minute, then normal service.
Recommendations
- Add a dedicated rate limit for the targeted route.
- Enable authenticated origin pulls.
- Review allow-listed partner ranges quarterly.
The billing model is what got our finance team on board, honestly.
We moved from a scrubbing provider to always-on last year; time to mitigation went from minutes to basically nothing.
Clear and practical, thanks.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.