On Wednesday 20 July 2022 at 04:58 UTC, a cache-busting query flood targeted a tax authority portal customer in North America. The attack peaked at 689.1 million requests per second and lasted 45 minutes. Traffic originated from 1425 autonomous systems in 44 countries, predominantly residential proxy networks.
| Vector | cache-busting query flood |
| Peak | 689.1 million requests per second |
| Duration | 45 min |
| Time to mitigation | 0.427 s |
| Attack traffic reaching origin | 0.025% |
| Legitimate traffic challenged | 0.02% |
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 757 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
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Keep origin IPs out of public DNS history.
- Add a dedicated rate limit for the targeted route.
- Enable authenticated origin pulls.
Nice to read a vendor blog that admits what went wrong.
Nice to read a vendor blog that admits what went wrong.
The billing model is what got our finance team on board, honestly.
Clear and practical, thanks.
This matches what we see in iGaming around big matches.