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Detectionmediumtest

PowerShell Module File Created By Non-PowerShell Process

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

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Launch
Nasreddine Bencherchali (Nextron Systems)Created Tue May 09Updated Tue Oct 07e3845023-ca9a-4024-b2b2-5422156d5527windows
Log Source
WindowsFile Event
ProductWindows← raw: windows
CategoryFile Event← raw: file_event

Events for file system activity including creation, modification, and deletion.

Detection Logic
Detection Logic3 selectors
detection:
    selection:
        TargetFilename|contains:
            - '\WindowsPowerShell\Modules\'
            - '\PowerShell\7\Modules\'
    filter_main_pwsh:
        Image|endswith:
            - ':\Program Files\PowerShell\7-preview\pwsh.exe'
            - ':\Program Files\PowerShell\7\pwsh.exe'
            - ':\Windows\System32\poqexec.exe' # https://github.com/SigmaHQ/sigma/issues/4448
            - ':\Windows\System32\WindowsPowerShell\v1.0\powershell_ise.exe'
            - ':\Windows\System32\WindowsPowerShell\v1.0\powershell.exe'
            - ':\Windows\SysWOW64\poqexec.exe' # https://github.com/SigmaHQ/sigma/issues/4448
            - ':\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell_ise.exe'
            - ':\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe'
    filter_main_msiexec:
        Image:
            - 'C:\Windows\System32\msiexec.exe'
            - 'C:\Windows\SysWOW64\msiexec.exe'
    condition: selection and not 1 of filter_main_*
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

References
1
Resolving title…
Internal Research
2
Resolving title…
learn.microsoft.com
MITRE ATT&CK
Rule Metadata
Rule ID
e3845023-ca9a-4024-b2b2-5422156d5527
Status
test
Level
medium
Type
Detection
Created
Tue May 09
Modified
Tue Oct 07
Author
Nasreddine Bencherchali (Nextron Systems)
Path
rules/windows/file/file_event/file_event_win_powershell_module_uncommon_creation.yml
Raw Tags
attack.persistence
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