On Friday 8 October 2021 at 08:15 UTC, a HTTP POST flood targeted a developer platform customer in Iberia. The attack peaked at 962.9 million requests per second and lasted 91 minutes. Traffic originated from 2518 autonomous systems in 60 countries, predominantly hijacked home routers.
| Vector | HTTP POST flood |
| Peak | 962.9 million requests per second |
| Duration | 91 min |
| Time to mitigation | 0.380 s |
| Attack traffic reaching origin | 0.079% |
| Legitimate traffic challenged | 0.33% |
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 290 within 6 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.
- Enable log streaming to your SIEM for faster correlation.
- Keep origin IPs out of public DNS history.
Clear and practical, thanks.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
We moved from a scrubbing provider to always-on last year; time to mitigation went from minutes to basically nothing.
Machine-readable ranges are at /ips.json and via the API.
The point about origin IPs leaking through certificate transparency logs is underrated.