On Sunday 27 November 2022 at 08:16 UTC, a GRE flood targeted a online casino customer in Western Europe. The attack peaked at 142.8 Gbps and lasted 165 minutes. Traffic originated from 4085 autonomous systems in 102 countries, predominantly compromised cloud VMs.
| Vector | GRE flood |
| Peak | 142.8 Gbps |
| Duration | 165 min |
| Time to mitigation | 0.150 s |
| Attack traffic reaching origin | 0.048% |
| Legitimate traffic challenged | 0.13% |
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 19 points of presence.
What the customer saw
No customer-visible impact. The on-call engineer was notified and acknowledged the incident from the dashboard.
Recommendations
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.
- Add a dedicated rate limit for the targeted route.
The point about origin IPs leaking through certificate transparency logs is underrated.
Thanks — sharing this with our on-call team.
Carpet bombing is nasty. Good to see a clear explanation of it.