On Sunday 28 August 2022 at 12:01 UTC, a WebSocket connection flood targeted a retail banking customer in Central Europe. The attack peaked at 837.3 million requests per second and lasted 132 minutes. Traffic originated from 2166 autonomous systems in 22 countries, predominantly mobile carrier ranges.
| Vector | WebSocket connection flood |
| Peak | 837.3 million requests per second |
| Duration | 132 min |
| Time to mitigation | 0.887 s |
| Attack traffic reaching origin | 0.065% |
| Legitimate traffic challenged | 0.59% |
Timeline
The attack was preceded by a ransom note demanding payment in Monero. Request rates on the targeted routes exceeded their hourly baseline by a factor of 506 within 9 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
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Keep origin IPs out of public DNS history.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.