On Wednesday 22 December 2021 at 10:54 UTC, a SYN flood targeted a online casino customer in the Benelux. The attack peaked at 77.0 Gbps and lasted 178 minutes. Traffic originated from 1272 autonomous systems in 94 countries, predominantly a headless-browser farm.
| Vector | SYN flood |
| Peak | 77.0 Gbps |
| Duration | 178 min |
| Time to mitigation | 0.005 s |
| Attack traffic reaching origin | 0.042% |
| Legitimate traffic challenged | 0.27% |
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 22 points of presence.
What the customer saw
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Enable log streaming to your SIEM for faster correlation.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Keep origin IPs out of public DNS history.
Great write-up. We saw almost the same pattern on our login endpoint last month.
Could you share the dataset behind the percentages?