On Wednesday 18 June 2025 at 23:37 UTC, a GRE flood targeted a fashion retail customer in the Nordics. The attack peaked at 46.2 Gbps and lasted 169 minutes. Traffic originated from 3590 autonomous systems in 21 countries, predominantly misconfigured open reflectors.
| Vector | GRE flood |
| Peak | 46.2 Gbps |
| Duration | 169 min |
| Time to mitigation | 0.638 s |
| Attack traffic reaching origin | 0.080% |
| Legitimate traffic challenged | 0.29% |
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 38 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
- Enable log streaming to your SIEM for faster correlation.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.