On Tuesday 13 August 2024 at 05:22 UTC, a WebSocket connection flood targeted a ticketing customer in the UK. The attack peaked at 424.0 million requests per second and lasted 40 minutes. Traffic originated from 3961 autonomous systems in 112 countries, predominantly compromised cloud VMs.
| Vector | WebSocket connection flood |
| Peak | 424.0 million requests per second |
| Duration | 40 min |
| Time to mitigation | 0.350 s |
| Attack traffic reaching origin | 0.082% |
| Legitimate traffic challenged | 0.53% |
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 840 within 40 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 216 ms during the first minute, then normal service.
Recommendations
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.
- Enable log streaming to your SIEM for faster correlation.
Carpet bombing is nasty. Good to see a clear explanation of it.
Our auditors asked for exactly this kind of incident evidence under DORA.