On Friday 15 August 2025 at 07:05 UTC, a Slowloris targeted a developer platform customer in the Nordics. The attack peaked at 702.4 million requests per second and lasted 51 minutes. Traffic originated from 1523 autonomous systems in 7 countries, predominantly a headless-browser farm.
| Vector | Slowloris |
| Peak | 702.4 million requests per second |
| Duration | 51 min |
| Time to mitigation | 0.229 s |
| Attack traffic reaching origin | 0.078% |
| Legitimate traffic challenged | 0.39% |
Timeline
The attack was preceded by a publicly announced sales event. Request rates on the targeted routes exceeded their hourly baseline by a factor of 335 within 30 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
- Review allow-listed partner ranges quarterly.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable log streaming to your SIEM for faster correlation.