On Thursday 15 April 2021 at 23:51 UTC, a HTTP POST flood targeted a airline booking customer in the UK. The attack peaked at 589.6 million requests per second and lasted 113 minutes. Traffic originated from 2060 autonomous systems in 62 countries, predominantly a rented booter service.
| Vector | HTTP POST flood |
| Peak | 589.6 million requests per second |
| Duration | 113 min |
| Time to mitigation | 0.006 s |
| Attack traffic reaching origin | 0.075% |
| Legitimate traffic challenged | 0.67% |
Timeline
The attack was preceded by a hacktivist channel announcing the target. Request rates on the targeted routes exceeded their hourly baseline by a factor of 301 within 24 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.
- Add a dedicated rate limit for the targeted route.
- Keep origin IPs out of public DNS history.
Do you publish the edge IP ranges in a machine-readable format?
Our auditors asked for exactly this kind of incident evidence under DORA.
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