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Detectionmediumtest

Unsigned AppX Installation Attempt Using Add-AppxPackage - PsScript

Detects usage of the "Add-AppxPackage" or it's alias "Add-AppPackage" to install unsigned AppX packages

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Launch
Nasreddine Bencherchali (Nextron Systems)Created Tue Jan 31975b2262-9a49-439d-92a6-0709cccdf0b2windows
Log Source
WindowsPowerShell Script
ProductWindows← raw: windows
CategoryPowerShell Script← raw: ps_script

Definition

Script Block Logging must be enable

Detection Logic
Detection Logic2 selectors
detection:
    selection_cmdlet:
        ScriptBlockText|contains:
            - 'Add-AppPackage '
            - 'Add-AppxPackage '
    selection_flag:
        ScriptBlockText|contains: ' -AllowUnsigned'
    condition: all of selection_*
False Positives

Installation of unsigned packages for testing purposes

References
1
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learn.microsoft.com
2
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twitter.com
MITRE ATT&CK
Related Rules
SimilarDetectionmedium

Unsigned AppX Installation Attempt Using Add-AppxPackage

Detects usage of the "Add-AppxPackage" or it's alias "Add-AppPackage" to install unsigned AppX packages

Detects similar activity. Both rules may fire on overlapping events.

SimilarDetectionmedium

Windows AppX Deployment Unsigned Package Installation

Detects attempts to install unsigned MSIX/AppX packages using the -AllowUnsigned parameter via AppXDeployment-Server events

Detects similar activity. Both rules may fire on overlapping events.

Rule Metadata
Rule ID
975b2262-9a49-439d-92a6-0709cccdf0b2
Status
test
Level
medium
Type
Detection
Created
Tue Jan 31
Author
Nasreddine Bencherchali (Nextron Systems)
Path
rules/windows/powershell/powershell_script/posh_ps_install_unsigned_appx_packages.yml
Raw Tags
attack.persistenceattack.defense-evasion
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