On Tuesday 22 March 2022 at 03:53 UTC, a cache-busting query flood targeted a news publisher customer in Southeast Asia. The attack peaked at 720.7 million requests per second and lasted 77 minutes. Traffic originated from 4026 autonomous systems in 18 countries, predominantly mobile carrier ranges.
| Vector | cache-busting query flood |
| Peak | 720.7 million requests per second |
| Duration | 77 min |
| Time to mitigation | 0.173 s |
| Attack traffic reaching origin | 0.014% |
| Legitimate traffic challenged | 0.36% |
Timeline
The attack was preceded by a competitor’s product launch. Request rates on the targeted routes exceeded their hourly baseline by a factor of 771 within 18 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.
- Add a dedicated rate limit for the targeted route.
- Lower challenge thresholds on authentication endpoints during high-risk events.