Execution of Powershell Script in Public Folder

Severity: high
Author: Max Altgelt (Nextron Systems)
Source: upstream

This rule detects execution of PowerShell scripts located in the "C:\Users\Public" folder

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059.001` Command and Scripting Interpreter: PowerShell

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation
Security-Auditing	4688	A new process has been created.

Stages and Predicates

Stage 1: `selection`

or:
CommandLine|contains: '-f %Public%'
CommandLine|contains: '-f C:\Users\Public'
CommandLine|contains: '-f "C:\Users\Public'
CommandLine|contains: '-fi %Public%'
CommandLine|contains: '-fi C:\Users\Public'
CommandLine|contains: '-fi "C:\Users\Public'
CommandLine|contains: '-fil %Public%'
CommandLine|contains: '-fil C:\Users\Public'
CommandLine|contains: '-fil "C:\Users\Public'
CommandLine|contains: '-file %Public%'
CommandLine|contains: '-file C:\Users\Public'
CommandLine|contains: '-file "C:\Users\Public'
or:
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.