On Monday 5 February 2024 at 01:38 UTC, a TLS handshake exhaustion targeted a crypto exchange customer in Latin America. The attack peaked at 54.3 million requests per second and lasted 58 minutes. Traffic originated from 1638 autonomous systems in 61 countries, predominantly mobile carrier ranges.
| Vector | TLS handshake exhaustion |
| Peak | 54.3 million requests per second |
| Duration | 58 min |
| Time to mitigation | 0.339 s |
| Attack traffic reaching origin | 0.064% |
| Legitimate traffic challenged | 0.05% |
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 852 within 18 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
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.
- Enable log streaming to your SIEM for faster correlation.