On Wednesday 11 January 2023 at 21:49 UTC, a HTTP GET flood targeted a B2B SaaS customer in the UK. The attack peaked at 472.2 million requests per second and lasted 132 minutes. Traffic originated from 535 autonomous systems in 29 countries, predominantly mobile carrier ranges.
| Vector | HTTP GET flood |
| Peak | 472.2 million requests per second |
| Duration | 132 min |
| Time to mitigation | 0.438 s |
| Attack traffic reaching origin | 0.006% |
| Legitimate traffic challenged | 0.56% |
Timeline
The attack was preceded by a competitor’s product launch. Request rates on the targeted routes exceeded their hourly baseline by a factor of 713 within 40 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.
- Keep origin IPs out of public DNS history.
- Lower challenge thresholds on authentication endpoints during high-risk events.
The billing model is what got our finance team on board, honestly.
We moved from a scrubbing provider to always-on last year; time to mitigation went from minutes to basically nothing.
The point about origin IPs leaking through certificate transparency logs is underrated.
The billing model is what got our finance team on board, honestly.
This matches what we see in iGaming around big matches.
Good question. We will cover that in a follow-up post.
This matches what we see in iGaming around big matches.
Great to hear, thanks for sharing your experience.