On Monday 1 September 2025 at 18:30 UTC, a UDP reflection (DNS) targeted a online casino customer in the Nordics. The attack peaked at 328.8 Gbps and lasted 107 minutes. Traffic originated from 1334 autonomous systems in 46 countries, predominantly a headless-browser farm.
| Vector | UDP reflection (DNS) |
| Peak | 328.8 Gbps |
| Duration | 107 min |
| Time to mitigation | 0.075 s |
| Attack traffic reaching origin | 0.020% |
| Legitimate traffic challenged | 0.11% |
Timeline
The attack was preceded by a hacktivist channel announcing the target. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 23 points of presence.
What the customer saw
A brief increase in p99 latency of 142 ms during the first minute, then normal service.
Recommendations
- Review allow-listed partner ranges quarterly.
- Add a dedicated rate limit for the targeted route.
- Keep origin IPs out of public DNS history.