On Monday 19 August 2024 at 07:29 UTC, a SYN flood targeted a retail banking customer in Central Europe. The attack peaked at 96.8 Gbps and lasted 43 minutes. Traffic originated from 1948 autonomous systems in 97 countries, predominantly mobile carrier ranges.
| Vector | SYN flood |
| Peak | 96.8 Gbps |
| Duration | 43 min |
| Time to mitigation | 0.777 s |
| Attack traffic reaching origin | 0.009% |
| Legitimate traffic challenged | 0.47% |
Timeline
The attack was preceded by no stated motive. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 27 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Enable log streaming to your SIEM for faster correlation.
- Enable authenticated origin pulls.
- Keep origin IPs out of public DNS history.
Great write-up. We saw almost the same pattern on our login endpoint last month.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Machine-readable ranges are at /ips.json and via the API.
Any plans to support per-tenant limits keyed on a JWT claim?
How do you avoid challenging uptime monitors and partners?