On Saturday 17 May 2025 at 06:21 UTC, a SYN flood targeted a online casino customer in Central Europe. The attack peaked at 138.6 Gbps and lasted 15 minutes. Traffic originated from 1746 autonomous systems in 40 countries, predominantly residential proxy networks.
| Vector | SYN flood |
| Peak | 138.6 Gbps |
| Duration | 15 min |
| Time to mitigation | 0.852 s |
| Attack traffic reaching origin | 0.061% |
| Legitimate traffic challenged | 0.79% |
Timeline
The attack was preceded by a breaking political story. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 28 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.
- Add a dedicated rate limit for the targeted route.
- Enable authenticated origin pulls.
Our auditors asked for exactly this kind of incident evidence under DORA.