Testing Usage of Uncommonly Used Port

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About the rule

Rule Type

Standard

Rule Description

Adversaries may communicate using a protocol and port paring that are typically not associated. For example, HTTPS over port 8088(Citation: Symantec Elfin Mar 2019) or port 587(Citation: Fortinet Agent Tesla April 2018) as opposed to the traditional port 443.

Severity

Trouble

Rule Requirement

Criteria

Action1: actionname = "PowerShell Script Block Logged" AND (SCRIPTEXECUTED contains "Test-NetConnection" AND SCRIPTEXECUTED contains "-ComputerName " AND SCRIPTEXECUTED contains "-port ") AND SCRIPTEXECUTED notcontains " 443 , 80 " select Action1.HOSTNAME,Action1.MESSAGE,Action1.SCRIPTEXECUTED

Detection

Execution Mode

realtime

Log Sources

Windows

Author

frack113