Detection rules › Sigma

PowerShell Module File Created

Status
test
Severity
low
Log source
category file_event, product windows
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

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

Known false positives

  • Likely

MITRE ATT&CK coverage

TacticTechniques
PersistenceNo specific technique

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 11: FileCreate

Rule body

title: PowerShell Module File Created
id: e36941d0-c0f0-443f-bc6f-cb2952eb69ea
status: test
description: Detects the creation of a new PowerShell module ".psm1", ".psd1", ".dll", ".ps1", etc.
references:
    - Internal Research
    - https://learn.microsoft.com/en-us/powershell/scripting/developer/module/understanding-a-windows-powershell-module?view=powershell-7.3
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-09
tags:
    - attack.persistence
logsource:
    category: file_event
    product: windows
detection:
    selection:
        Image|endswith:
            - '\powershell.exe'
            - '\pwsh.exe'
        TargetFilename|contains:
            - '\WindowsPowerShell\Modules\'
            - '\PowerShell\7\Modules\'
    condition: selection
falsepositives:
    - Likely
level: low

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

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

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • \powershell.exe corpus 179 (sigma 178, kusto 1)
  • \pwsh.exe corpus 165 (sigma 164, kusto 1)
field:"Image" kind:ends_with
TargetFilenamematch
  • \PowerShell\7\Modules\ corpus 2 (sigma 2)
  • \WindowsPowerShell\Modules\ corpus 2 (sigma 2)
field:"TargetFilename" kind:match