On Tuesday 29 October 2024 at 09:07 UTC, a GRE flood targeted a B2B SaaS customer in the UK. The attack peaked at 375.1 Gbps and lasted 74 minutes. Traffic originated from 1863 autonomous systems in 41 countries, predominantly compromised cloud VMs.
| Vector | GRE flood |
| Peak | 375.1 Gbps |
| Duration | 74 min |
| Time to mitigation | 0.490 s |
| Attack traffic reaching origin | 0.060% |
| Legitimate traffic challenged | 0.77% |
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 17 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
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.
- Keep origin IPs out of public DNS history.