Internal port scanning against SSH/HTTP/SMB/RDP from compromised host
This rule detects rapid, repetitive connection attempts (TCP SYN) from a source within the internal network to a set of high-value targets (SSH, HTTP, SMB, RDP ports) within the same internal network. Such patterns are indicative of lateral movement or internal network reconnaissance, often performed by adversaries pivoting through a compromised host to discover services on other internal systems.
Suricata

