Detection rules › Sigma

Potential Suspicious PowerShell Module File Created

Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Source
upstream

Detects the creation of a new PowerShell module in the first folder of the module directory structure "\WindowsPowerShell\Modules\malware\malware.psm1". This is somewhat an uncommon practice as legitimate modules often includes a version folder.

Event coverage

ProviderEvent IDTitle
Sysmon11FileCreate

Stages and Predicates

Stage 1: selection

or:
TargetFilename|endswith: '\\WindowsPowerShell\\Modules\\*\.dll'
TargetFilename|endswith: '\\WindowsPowerShell\\Modules\\*\.ps'

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.

FieldKindValues
TargetFilenameends_with
  • \\WindowsPowerShell\\Modules\\*\.dll
  • \\WindowsPowerShell\\Modules\\*\.ps