The rule "Potential Internal Linux SSH Brute Force Detected" identifies potential brute force login attempts targeting user accounts via SSH on Linux systems. It tracks multiple, consecutive login failures from the same source IP address directed towards a single user account within a short timeframe. This behavior is indicative of adversaries trying different credentials, often leveraging common or known passwords to gain unauthorized access. The rule utilizes EQL to analyze logs from Filebeat and system authentication logs to alert on these suspicious activities. It recommends specific investigation steps, including reviewing failed login attempts, analyzing the source IP, and checking for other associated alerts within a recent window. Additionally, it provides insights on potential false positives, such as account misconfigurations and service account issues, along with a comprehensive incident response strategy if a potential attack is confirmed.