On Wednesday 17 December 2025 at 14:49 UTC, a ACK flood targeted a ticketing customer in the Nordics. The attack peaked at 352.3 Gbps and lasted 105 minutes. Traffic originated from 3092 autonomous systems in 51 countries, predominantly residential proxy networks.
| Vector | ACK flood |
| Peak | 352.3 Gbps |
| Duration | 105 min |
| Time to mitigation | 0.450 s |
| Attack traffic reaching origin | 0.076% |
| Legitimate traffic challenged | 0.20% |
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 32 points of presence.
What the customer saw
No customer-visible impact. The on-call engineer was notified and acknowledged the incident from the dashboard.
Recommendations
- Add a dedicated rate limit for the targeted route.
- Enable log streaming to your SIEM for faster correlation.
- Enable authenticated origin pulls.