sigmalowHunting

Import New Module Via PowerShell CommandLine

Detects usage of the "Import-Module" cmdlet in order to add new Cmdlets to the current PowerShell session

Detection Query

selection_img:
  - Image|endswith:
      - \powershell.exe
      - \pwsh.exe
  - OriginalFileName:
      - PowerShell.EXE
      - pwsh.dll
selection_cmdlet:
  CommandLine|contains:
    - "Import-Module "
    - "ipmo "
filter_main_vsstudio:
  ParentImage|contains:
    - :\Program Files\WindowsApps\Microsoft.WindowsTerminal_
    - :\Windows\System32\cmd.exe
  CommandLine|contains|all:
    - :\Program Files\Microsoft Visual Studio\
    - Tools\Microsoft.VisualStudio.DevShell.dll
condition: all of selection_* and not 1 of filter_main_*

Author

Nasreddine Bencherchali (Nextron Systems)

Created

2023-05-09

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.executiondetection.threat-hunting

Raw Content

title: Import New Module Via PowerShell CommandLine
id: 4ad74d01-f48c-42d0-b88c-b31efa4d2262
status: test
description: Detects usage of the "Import-Module" cmdlet in order to add new Cmdlets to the current PowerShell session
references:
    - https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/import-module?view=powershell-7.3
    - https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/import-module?view=powershell-5.1
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-09
modified: 2023-12-01
tags:
    - attack.execution
    - detection.threat-hunting
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        - Image|endswith:
              - '\powershell.exe'
              - '\pwsh.exe'
        - OriginalFileName:
              - 'PowerShell.EXE'
              - 'pwsh.dll'
    selection_cmdlet:
        CommandLine|contains:
            - 'Import-Module '
            - 'ipmo '
    filter_main_vsstudio:
        ParentImage|contains:
            - ':\Program Files\WindowsApps\Microsoft.WindowsTerminal_'
            - ':\Windows\System32\cmd.exe'
        CommandLine|contains|all:
            - ':\Program Files\Microsoft Visual Studio\'
            - 'Tools\Microsoft.VisualStudio.DevShell.dll'
    condition: all of selection_* and not 1 of filter_main_*
falsepositives:
    - Depending on the environement, many legitimate scripts will import modules inline. This rule is targeted for hunting purposes.
level: low