On Friday 28 May 2021 at 14:41 UTC, a search endpoint flood targeted a tax authority portal customer in Latin America. The attack peaked at 919.1 million requests per second and lasted 144 minutes. Traffic originated from 1490 autonomous systems in 49 countries, predominantly a rented booter service.
| Vector | search endpoint flood |
| Peak | 919.1 million requests per second |
| Duration | 144 min |
| Time to mitigation | 0.667 s |
| Attack traffic reaching origin | 0.076% |
| Legitimate traffic challenged | 0.67% |
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 516 within 23 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 76 ms during the first minute, then normal service.
Recommendations
- Review allow-listed partner ranges quarterly.
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.