On Wednesday 19 July 2023 at 14:36 UTC, a ACK flood targeted a online casino customer in the Nordics. The attack peaked at 15.6 Gbps and lasted 42 minutes. Traffic originated from 1948 autonomous systems in 56 countries, predominantly a rented booter service.
| Vector | ACK flood |
| Peak | 15.6 Gbps |
| Duration | 42 min |
| Time to mitigation | 0.489 s |
| Attack traffic reaching origin | 0.039% |
| Legitimate traffic challenged | 0.17% |
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 31 points of presence.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Add a dedicated rate limit for the targeted route.
- Enable log streaming to your SIEM for faster correlation.
- Review allow-listed partner ranges quarterly.