On Friday 11 February 2022 at 16:38 UTC, a ACK flood targeted a ticketing customer in the Benelux. The attack peaked at 15.4 Gbps and lasted 55 minutes. Traffic originated from 3672 autonomous systems in 41 countries, predominantly a headless-browser farm.
| Vector | ACK flood |
| Peak | 15.4 Gbps |
| Duration | 55 min |
| Time to mitigation | 0.150 s |
| Attack traffic reaching origin | 0.065% |
| Legitimate traffic challenged | 0.70% |
Timeline
The attack was preceded by a publicly announced sales event. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 17 points of presence.
What the customer saw
A brief increase in p99 latency of 192 ms during the first minute, then normal service.
Recommendations
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.
- Review allow-listed partner ranges quarterly.