On Thursday 4 May 2023 at 09:16 UTC, a HTTP GET flood targeted a video streaming customer in the UK. The attack peaked at 483.4 million requests per second and lasted 84 minutes. Traffic originated from 2011 autonomous systems in 66 countries, predominantly compromised cloud VMs.
| Vector | HTTP GET flood |
| Peak | 483.4 million requests per second |
| Duration | 84 min |
| Time to mitigation | 0.261 s |
| Attack traffic reaching origin | 0.032% |
| Legitimate traffic challenged | 0.07% |
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 50 within 18 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
A brief increase in p99 latency of 205 ms during the first minute, then normal service.
Recommendations
- Review allow-listed partner ranges quarterly.
- Add a dedicated rate limit for the targeted route.
- Keep origin IPs out of public DNS history.