PowerShell Scripts Installed as Services - Security

Severity: high
Author: oscd.community, Natalia Shornikova
Source: upstream

Detects powershell script installed as a Service

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1569.002` System Services: Service Execution

Event coverage

Provider	Event ID	Title
Security-Auditing	4697	A service was installed in the system.

Stages and Predicates

Stage 1: `selection`

or:
ServiceFileName|contains: powershell
ServiceFileName|contains: pwsh

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.

Field	Kind	Values
`ServiceFileName`	match	`powershell` corpus 4 (sigma 4) `pwsh`

Neighbors

Broader alternatives (more inclusive than this rule)

These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.

CobaltStrike Service Installations - Security [sigma] (drops 1 filter this rule applies) (first-stage match only; downstream stages may differ)
Invoke-Obfuscation Obfuscated IEX Invocation - Security [sigma] (drops 1 filter this rule applies) (first-stage match only; downstream stages may differ)
Meterpreter or Cobalt Strike Getsystem Service Installation - Security [sigma] (drops 1 filter this rule applies) (first-stage match only; downstream stages may differ)
Service Installed By Unusual Client - Security [sigma] (drops 1 filter this rule applies) (first-stage match only; downstream stages may differ)