On Saturday 5 October 2024 at 19:20 UTC, a SYN flood targeted a B2B SaaS customer in the Benelux. The attack peaked at 354.2 Gbps and lasted 10 minutes. Traffic originated from 890 autonomous systems in 24 countries, predominantly residential proxy networks.
| Vector | SYN flood |
| Peak | 354.2 Gbps |
| Duration | 10 min |
| Time to mitigation | 0.128 s |
| Attack traffic reaching origin | 0.012% |
| Legitimate traffic challenged | 0.29% |
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 20 points of presence.
What the customer saw
A brief increase in p99 latency of 66 ms during the first minute, then normal service.
Recommendations
- Enable authenticated origin pulls.
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.