On Thursday 13 June 2024 at 10:57 UTC, a SYN flood targeted a news publisher customer in the Benelux. The attack peaked at 27.9 Gbps and lasted 24 minutes. Traffic originated from 4124 autonomous systems in 81 countries, predominantly hijacked home routers.
| Vector | SYN flood |
| Peak | 27.9 Gbps |
| Duration | 24 min |
| Time to mitigation | 0.836 s |
| Attack traffic reaching origin | 0.018% |
| Legitimate traffic challenged | 0.07% |
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 13 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
- Keep origin IPs out of public DNS history.
- Review allow-listed partner ranges quarterly.
- Add a dedicated rate limit for the targeted route.
How do you avoid challenging uptime monitors and partners?