On Thursday 23 December 2021 at 20:28 UTC, a search endpoint flood targeted a tax authority portal customer in the Middle East. The attack peaked at 901.9 million requests per second and lasted 129 minutes. Traffic originated from 2636 autonomous systems in 109 countries, predominantly a headless-browser farm.
| Vector | search endpoint flood |
| Peak | 901.9 million requests per second |
| Duration | 129 min |
| Time to mitigation | 0.403 s |
| Attack traffic reaching origin | 0.068% |
| Legitimate traffic challenged | 0.16% |
Timeline
The attack was preceded by a ransom note demanding payment in Monero. Request rates on the targeted routes exceeded their hourly baseline by a factor of 293 within 32 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
- Add a dedicated rate limit for the targeted route.
- Enable log streaming to your SIEM for faster correlation.
- Keep origin IPs out of public DNS history.
Nice to read a vendor blog that admits what went wrong.