Critical System Binary Overwritten via SMB

Darshan Thummar@Mighty

•updated Jun 11, 2026•0•0•3

This rule detects attempts to overwrite critical system binaries (specifically executables in 'system32') via Server Message Block (SMB) protocol. It looks for SMB traffic to port 445, containing 'system32' and '.exe' (case-insensitive), with a payload size greater than 100,000 bytes, indicating a potential file transfer or modification of a large executable.