C2 Commands Read from Removable Media Share

Darshan Thummar@Mighty

•updated Jun 12, 2026•0•0•1

This rule detects potential command and control (C2) activity where commands are being read from a removable media share over SMB. It specifically looks for SMB traffic containing the string "USBSTOR" (case-insensitive) and ".txt" (case-insensitive), indicating access to text files on a USB storage device. A threshold of 5 occurrences within 30 seconds from the same source IP is applied to reduce false positives.