On Saturday 28 December 2024 at 01:59 UTC, a TLS handshake exhaustion targeted a electronics retail customer in Central Europe. The attack peaked at 318.2 million requests per second and lasted 146 minutes. Traffic originated from 2218 autonomous systems in 35 countries, predominantly mobile carrier ranges.
| Vector | TLS handshake exhaustion |
| Peak | 318.2 million requests per second |
| Duration | 146 min |
| Time to mitigation | 0.689 s |
| Attack traffic reaching origin | 0.070% |
| Legitimate traffic challenged | 0.31% |
Timeline
The attack was preceded by a competitor’s product launch. Request rates on the targeted routes exceeded their hourly baseline by a factor of 578 within 21 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
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable authenticated origin pulls.
- Keep origin IPs out of public DNS history.