Sigma rule: AppX Located in Uncommon Directory Added to Deployment Pipeline

Rule

Title

AppX Located in Uncommon Directory Added to Deployment Pipeline

Status

test

Level

medium

Author

Nasreddine Bencherchali (Nextron Systems)

Date

2023-01-11

Modified

2025-12-03

File

rules/windows/builtin/appxdeployment_server/win_appxdeployment_server_uncommon_package_locations.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects an appx package that was added to the pipeline of the "to be processed" packages that is located in uncommon locations.

Log source

product

windows

service

appxdeployment-server

Detection

selection:
    EventID: 854
filter_main_generic:
    Path|contains:
        # Paths can be written using forward slash if the "file://" protocol is used
        - ':/Program%20Files' # Also covers 'file:///C:/Program%20Files%20(x86)/'
        - ':/Windows/System32/'
        - ':\Program Files (x86)\'
        - ':\Program Files\'
        - ':\Windows\ImmersiveControlPanel\'
        - ':\Windows\PrintDialog\'
        - ':\Windows\SystemApps\'
        - 'AppData/Local/Temp/WinGet/Microsoft.Winget.Source'
        - 'x-windowsupdate://'
filter_main_specific:
    Path|contains:
        - 'https://installer.teams.static.microsoft/'
        - 'https://res.cdn.office.net' # Example https://res.cdn.office.net/nativehost/5mttl/installer/v2/1.2025.617.100/Microsoft.OutlookForWindows_x64.msix
        - 'https://statics.teams.cdn.live.net/'
        - 'https://statics.teams.cdn.office.net/'
        - 'microsoft.com' # Example: https://go.microsoft.com/fwlink/?linkid=2160968
filter_optional_onedrive:
    Path|contains: 'AppData\Local\Microsoft\OneDrive\'
filter_optional_winget:
    Path|contains:
        - 'AppData/Local/Temp/WinGet/Microsoft.Winget.Source'
        - 'AppData\Local\Temp\WinGet\Microsoft.Winget.Source'
filter_optional_x_windowsupdate:
    Path|contains: 'x-windowsupdate://'
condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.stealth

References

• Internal Research
• https://www.sentinelone.com/labs/inside-malicious-windows-apps-for-malware-deployment/
• https://learn.microsoft.com/en-us/windows/win32/appxpkg/troubleshooting
• https://news.sophos.com/en-us/2021/11/11/bazarloader-call-me-back-attack-abuses-windows-10-apps-mechanism/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/appxdeployment_server/win_appxdeployment_server_uncommon_package_locations.yml