On Saturday 28 September 2024 at 04:33 UTC, a cache-busting query flood targeted a sports betting customer in the UK. The attack peaked at 625.3 million requests per second and lasted 66 minutes. Traffic originated from 3430 autonomous systems in 53 countries, predominantly misconfigured open reflectors.
| Vector | cache-busting query flood |
| Peak | 625.3 million requests per second |
| Duration | 66 min |
| Time to mitigation | 0.809 s |
| Attack traffic reaching origin | 0.076% |
| Legitimate traffic challenged | 0.37% |
Timeline
The attack was preceded by an extortion email received two days earlier. Request rates on the targeted routes exceeded their hourly baseline by a factor of 773 within 37 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
- Enable log streaming to your SIEM for faster correlation.
- Add a dedicated rate limit for the targeted route.
- Keep origin IPs out of public DNS history.
Nice to read a vendor blog that admits what went wrong.
Do you publish the edge IP ranges in a machine-readable format?
How do you avoid challenging uptime monitors and partners?