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AppX Package Deployment Failed Due to Signing Requirements

Detects an appx package deployment / installation with the error code "0x80073cff" which indicates that the package didn't meet the signing requirements.

Detection Query

selection:
  EventID: 401
  ErrorCode: "0x80073cff"
condition: selection

Author

Nasreddine Bencherchali (Nextron Systems)

Created

2023-01-11

Data Sources

windowsappxdeployment-server

Platforms

windows

References

Tags

attack.defense-evasion

Raw Content

title: AppX Package Deployment Failed Due to Signing Requirements
id: 898d5fc9-fbc3-43de-93ad-38e97237c344
status: test
description: |
    Detects an appx package deployment / installation with the error code "0x80073cff" which indicates that the package didn't meet the signing requirements.
references:
    - 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/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-01-11
modified: 2025-12-03
tags:
    - attack.defense-evasion
logsource:
    product: windows
    service: appxdeployment-server
detection:
    selection:
        EventID: 401
        ErrorCode: '0x80073cff' # Check ref section to learn more about this error code
    condition: selection
falsepositives:
    - Legitimate AppX packages not signed by MS used part of an enterprise.
level: medium