On Sunday 26 May 2024 at 20:36 UTC, a Slowloris targeted a video streaming customer in the Nordics. The attack peaked at 468.4 million requests per second and lasted 97 minutes. Traffic originated from 127 autonomous systems in 51 countries, predominantly compromised cloud VMs.
| Vector | Slowloris |
| Peak | 468.4 million requests per second |
| Duration | 97 min |
| Time to mitigation | 0.703 s |
| Attack traffic reaching origin | 0.067% |
| Legitimate traffic challenged | 0.44% |
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 96 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
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Enable log streaming to your SIEM for faster correlation.
- Add a dedicated rate limit for the targeted route.