On Monday 8 December 2025 at 14:39 UTC, a carpet-bombing UDP flood targeted a healthcare portal customer in Western Europe. The attack peaked at 251.8 Gbps and lasted 145 minutes. Traffic originated from 368 autonomous systems in 17 countries, predominantly a rented booter service.
| Vector | carpet-bombing UDP flood |
| Peak | 251.8 Gbps |
| Duration | 145 min |
| Time to mitigation | 0.165 s |
| Attack traffic reaching origin | 0.054% |
| Legitimate traffic challenged | 0.66% |
Timeline
The attack was preceded by an extortion email received two days earlier. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 17 points of presence.
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.
Great write-up. We saw almost the same pattern on our login endpoint last month.
The point about origin IPs leaking through certificate transparency logs is underrated.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
The point about origin IPs leaking through certificate transparency logs is underrated.
Verified good bots and allow-listed partners bypass challenges entirely.
Interesting that most attacks are under ten minutes. Our experience is similar.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Do you publish the edge IP ranges in a machine-readable format?
Clear and practical, thanks.
Good question. We will cover that in a follow-up post.