On Saturday 1 March 2025 at 20:00 UTC, a TLS handshake exhaustion targeted a online casino customer in the Benelux. The attack peaked at 875.6 million requests per second and lasted 35 minutes. Traffic originated from 1691 autonomous systems in 97 countries, predominantly a Mirai-derived IoT botnet.
| Vector | TLS handshake exhaustion |
| Peak | 875.6 million requests per second |
| Duration | 35 min |
| Time to mitigation | 0.806 s |
| Attack traffic reaching origin | 0.017% |
| Legitimate traffic challenged | 0.01% |
Timeline
The attack was preceded by no stated motive. Request rates on the targeted routes exceeded their hourly baseline by a factor of 796 within 25 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 195 ms during the first minute, then normal service.
Recommendations
- Keep origin IPs out of public DNS history.
- Enable log streaming to your SIEM for faster correlation.
- Enable authenticated origin pulls.