USB Drive Contents Exfiltrated via SSH SCP

Darshan Thummar@Mighty

•updated Jun 12, 2026•0•0•3

This rule detects potential data exfiltration of USB drive contents over SSH using SCP. It triggers when TCP traffic on port 22 (SSH) from the home network to the home network contains the string "/dev/sd" (case-insensitive) and the data size is greater than 65000 bytes. This combination suggests that a file from a Linux-like USB device (often mounted as /dev/sdX) is being transferred out via SCP.