On Saturday 27 December 2025 at 05:34 UTC, a Slowloris targeted a retail banking customer in Latin America. The attack peaked at 67.6 million requests per second and lasted 165 minutes. Traffic originated from 2531 autonomous systems in 41 countries, predominantly a headless-browser farm.
| Vector | Slowloris |
| Peak | 67.6 million requests per second |
| Duration | 165 min |
| Time to mitigation | 0.762 s |
| Attack traffic reaching origin | 0.088% |
| Legitimate traffic challenged | 0.61% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 94 within 11 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 203 ms during the first minute, then normal service.
Recommendations
- Keep origin IPs out of public DNS history.
- Enable log streaming to your SIEM for faster correlation.
- Review allow-listed partner ranges quarterly.
Any plans to support per-tenant limits keyed on a JWT claim?
The point about origin IPs leaking through certificate transparency logs is underrated.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Clear and practical, thanks.
Great write-up. We saw almost the same pattern on our login endpoint last month.
Interesting that most attacks are under ten minutes. Our experience is similar.