On Monday 29 March 2021 at 16:53 UTC, a search endpoint flood targeted a video streaming customer in North America. The attack peaked at 261.9 million requests per second and lasted 118 minutes. Traffic originated from 3223 autonomous systems in 78 countries, predominantly mobile carrier ranges.
| Vector | search endpoint flood |
| Peak | 261.9 million requests per second |
| Duration | 118 min |
| Time to mitigation | 0.162 s |
| Attack traffic reaching origin | 0.059% |
| Legitimate traffic challenged | 0.63% |
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 849 within 34 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
- Add a dedicated rate limit for the targeted route.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable log streaming to your SIEM for faster correlation.
How do you avoid challenging uptime monitors and partners?
Could you share the dataset behind the percentages?
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Great write-up. We saw almost the same pattern on our login endpoint last month.