PowerShell Module File Created

Severity: low
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects the creation of a new PowerShell module ".psm1", ".psd1", ".dll", ".ps1", etc.

Event coverage

Provider	Event ID	Title
Sysmon	11	FileCreate

Stages and Predicates

Stage 1: `selection`

or:
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
or:
TargetFilename|contains: '\PowerShell\7\Modules\'
TargetFilename|contains: '\WindowsPowerShell\Modules\'

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
`Image`	ends_with	`\powershell.exe` corpus 143 (sigma 143) `\pwsh.exe` corpus 140 (sigma 140)
`TargetFilename`	match	`\PowerShell\7\Modules\` corpus 2 (sigma 2) `\WindowsPowerShell\Modules\` corpus 3 (sigma 3)

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.

PowerShell Module File Created By Non-PowerShell Process [sigma] (drops 1 filter this rule applies) (first-stage match only; downstream stages may differ)