On Friday 19 May 2023 at 15:31 UTC, a credential stuffing targeted a video streaming customer in Iberia. The attack peaked at 301.9 million requests per second and lasted 4 minutes. Traffic originated from 2789 autonomous systems in 34 countries, predominantly mobile carrier ranges.
| Vector | credential stuffing |
| Peak | 301.9 million requests per second |
| Duration | 4 min |
| Time to mitigation | 0.805 s |
| Attack traffic reaching origin | 0.015% |
| Legitimate traffic challenged | 0.20% |
Timeline
The attack was preceded by an extortion email received two days earlier. Request rates on the targeted routes exceeded their hourly baseline by a factor of 787 within 5 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
- Enable log streaming to your SIEM for faster correlation.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.
Is the risk score exposed in the logs so we can build our own dashboards on it?
Interesting that most attacks are under ten minutes. Our experience is similar.
Interesting that most attacks are under ten minutes. Our experience is similar.