On Sunday 25 September 2022 at 17:17 UTC, a WebSocket connection flood targeted a retail banking customer in North America. The attack peaked at 236.4 million requests per second and lasted 12 minutes. Traffic originated from 2133 autonomous systems in 115 countries, predominantly misconfigured open reflectors.
| Vector | WebSocket connection flood |
| Peak | 236.4 million requests per second |
| Duration | 12 min |
| Time to mitigation | 0.557 s |
| Attack traffic reaching origin | 0.069% |
| Legitimate traffic challenged | 0.61% |
Timeline
The attack was preceded by a publicly announced sales event. Request rates on the targeted routes exceeded their hourly baseline by a factor of 155 within 30 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.
- Add a dedicated rate limit for the targeted route.
- Enable log streaming to your SIEM for faster correlation.