On Wednesday 23 July 2025 at 01:42 UTC, a HTTP POST flood targeted a B2B SaaS customer in the UK. The attack peaked at 460.4 million requests per second and lasted 167 minutes. Traffic originated from 3753 autonomous systems in 14 countries, predominantly hijacked home routers.
| Vector | HTTP POST flood |
| Peak | 460.4 million requests per second |
| Duration | 167 min |
| Time to mitigation | 0.523 s |
| Attack traffic reaching origin | 0.004% |
| Legitimate traffic challenged | 0.74% |
Timeline
The attack was preceded by no stated motive. Request rates on the targeted routes exceeded their hourly baseline by a factor of 90 within 19 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 207 ms during the first minute, then normal service.
Recommendations
- Add a dedicated rate limit for the targeted route.
- Keep origin IPs out of public DNS history.
- Enable log streaming to your SIEM for faster correlation.