Threat Bulletin 0466: Slowloris against a education platform platform in Southeast Asia

On Monday 5 December 2022 at 11:19 UTC, a Slowloris targeted a education platform customer in Southeast Asia. The attack peaked at 580.1 million requests per second and lasted 68 minutes. Traffic originated from 2565 autonomous systems in 116 countries, predominantly misconfigured open reflectors.

Timeline

The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 762 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

The customer’s status page stayed green throughout; they learned about the attack from our notification.

Recommendations

• Keep origin IPs out of public DNS history.
• Lower challenge thresholds on authentication endpoints during high-risk events.
• Add a dedicated rate limit for the targeted route.