On Sunday 15 December 2024 at 16:00 UTC, a search endpoint flood targeted a municipal services customer in Central Europe. The attack peaked at 314.5 million requests per second and lasted 139 minutes. Traffic originated from 2046 autonomous systems in 69 countries, predominantly compromised cloud VMs.
| Vector | search endpoint flood |
| Peak | 314.5 million requests per second |
| Duration | 139 min |
| Time to mitigation | 0.717 s |
| Attack traffic reaching origin | 0.018% |
| Legitimate traffic challenged | 0.54% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 63 within 15 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
A brief increase in p99 latency of 209 ms during the first minute, then normal service.
Recommendations
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.
- Enable authenticated origin pulls.
The point about origin IPs leaking through certificate transparency logs is underrated.
Clear and practical, thanks.
Our auditors asked for exactly this kind of incident evidence under DORA.
Would love a follow-up on how you handle HTTP/3 fingerprinting.
Is the risk score exposed in the logs so we can build our own dashboards on it?
Verified good bots and allow-listed partners bypass challenges entirely.
Thanks — sharing this with our on-call team.
How do you avoid challenging uptime monitors and partners?
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.