On Wednesday 13 December 2023 at 15:41 UTC, a GRE flood targeted a tax authority portal customer in the Benelux. The attack peaked at 133.4 Gbps and lasted 165 minutes. Traffic originated from 3938 autonomous systems in 22 countries, predominantly mobile carrier ranges.
| Vector | GRE flood |
| Peak | 133.4 Gbps |
| Duration | 165 min |
| Time to mitigation | 0.110 s |
| Attack traffic reaching origin | 0.029% |
| Legitimate traffic challenged | 0.73% |
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 16 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.
- Enable authenticated origin pulls.
- Review allow-listed partner ranges quarterly.