On Thursday 17 November 2022 at 05:47 UTC, a GRE flood targeted a tax authority portal customer in Western Europe. The attack peaked at 55.2 Gbps and lasted 167 minutes. Traffic originated from 2477 autonomous systems in 39 countries, predominantly hijacked home routers.
| Vector | GRE flood |
| Peak | 55.2 Gbps |
| Duration | 167 min |
| Time to mitigation | 0.612 s |
| Attack traffic reaching origin | 0.087% |
| Legitimate traffic challenged | 0.04% |
Timeline
The attack was preceded by a competitor’s product launch. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 13 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Keep origin IPs out of public DNS history.
- Add a dedicated rate limit for the targeted route.
- Lower challenge thresholds on authentication endpoints during high-risk events.