On Friday 7 March 2025 at 11:16 UTC, a ACK flood targeted a developer platform customer in Central Europe. The attack peaked at 113.6 Gbps and lasted 149 minutes. Traffic originated from 2471 autonomous systems in 23 countries, predominantly residential proxy networks.
| Vector | ACK flood |
| Peak | 113.6 Gbps |
| Duration | 149 min |
| Time to mitigation | 0.070 s |
| Attack traffic reaching origin | 0.004% |
| Legitimate traffic challenged | 0.20% |
Timeline
The attack was preceded by a competitor’s product launch. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 28 points of presence.
What the customer saw
A brief increase in p99 latency of 136 ms during the first minute, then normal service.
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.