On Saturday 19 March 2022 at 03:18 UTC, a WebSocket connection flood targeted a electronics retail customer in Southeast Asia. The attack peaked at 191.8 million requests per second and lasted 101 minutes. Traffic originated from 3173 autonomous systems in 105 countries, predominantly mobile carrier ranges.
| Vector | WebSocket connection flood |
| Peak | 191.8 million requests per second |
| Duration | 101 min |
| Time to mitigation | 0.277 s |
| Attack traffic reaching origin | 0.064% |
| Legitimate traffic challenged | 0.48% |
Timeline
The attack was preceded by no stated motive. Request rates on the targeted routes exceeded their hourly baseline by a factor of 655 within 16 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
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.
- Keep origin IPs out of public DNS history.
Nice to read a vendor blog that admits what went wrong.
The billing model is what got our finance team on board, honestly.
Nice to read a vendor blog that admits what went wrong.
Thanks! Yes — the risk score and its components are included in every log record.
Interesting that most attacks are under ten minutes. Our experience is similar.
Thanks — sharing this with our on-call team.
The point about origin IPs leaking through certificate transparency logs is underrated.
Great write-up. We saw almost the same pattern on our login endpoint last month.