On Monday 22 September 2025 at 22:46 UTC, a ACK flood targeted a education platform customer in Iberia. The attack peaked at 282.3 Gbps and lasted 97 minutes. Traffic originated from 477 autonomous systems in 110 countries, predominantly residential proxy networks.
| Vector | ACK flood |
| Peak | 282.3 Gbps |
| Duration | 97 min |
| Time to mitigation | 0.754 s |
| Attack traffic reaching origin | 0.016% |
| Legitimate traffic challenged | 0.30% |
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 29 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.
- Lower challenge thresholds on authentication endpoints during high-risk events.