On Thursday 18 December 2025 at 20:59 UTC, a ACK flood targeted a developer platform customer in the UK. The attack peaked at 14.6 Gbps and lasted 46 minutes. Traffic originated from 1791 autonomous systems in 106 countries, predominantly a Mirai-derived IoT botnet.
| Vector | ACK flood |
| Peak | 14.6 Gbps |
| Duration | 46 min |
| Time to mitigation | 0.279 s |
| Attack traffic reaching origin | 0.028% |
| Legitimate traffic challenged | 0.79% |
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 28 points of presence.
What the customer saw
A brief increase in p99 latency of 182 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.