On Monday 3 March 2025 at 12:18 UTC, a ACK flood targeted a municipal services customer in the Benelux. The attack peaked at 336.8 Gbps and lasted 118 minutes. Traffic originated from 1721 autonomous systems in 31 countries, predominantly mobile carrier ranges.
| Vector | ACK flood |
| Peak | 336.8 Gbps |
| Duration | 118 min |
| Time to mitigation | 0.611 s |
| Attack traffic reaching origin | 0.084% |
| Legitimate traffic challenged | 0.37% |
Timeline
The attack was preceded by no stated motive. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 29 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Add a dedicated rate limit for the targeted route.
- Keep origin IPs out of public DNS history.