On Sunday 19 May 2024 at 02:56 UTC, a TLS handshake exhaustion targeted a video streaming customer in Central Europe. The attack peaked at 585.2 million requests per second and lasted 173 minutes. Traffic originated from 3255 autonomous systems in 45 countries, predominantly a rented booter service.
| Vector | TLS handshake exhaustion |
| Peak | 585.2 million requests per second |
| Duration | 173 min |
| Time to mitigation | 0.035 s |
| Attack traffic reaching origin | 0.018% |
| Legitimate traffic challenged | 0.72% |
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 817 within 22 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
- Keep origin IPs out of public DNS history.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable authenticated origin pulls.