On Tuesday 1 October 2024 at 13:40 UTC, a SYN flood targeted a tax authority portal customer in Iberia. The attack peaked at 205.8 Gbps and lasted 6 minutes. Traffic originated from 1461 autonomous systems in 55 countries, predominantly a rented booter service.
| Vector | SYN flood |
| Peak | 205.8 Gbps |
| Duration | 6 min |
| Time to mitigation | 0.430 s |
| Attack traffic reaching origin | 0.077% |
| Legitimate traffic challenged | 0.17% |
Timeline
The attack was preceded by a ransom note demanding payment in Monero. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 19 points of presence.
What the customer saw
A brief increase in p99 latency of 213 ms during the first minute, then normal service.
Recommendations
- Enable log streaming to your SIEM for faster correlation.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Keep origin IPs out of public DNS history.