Office Autorun Keys Modification

Title: Office Autorun Keys Modification
Status: test
Description:Detects modification of autostart extensibility point (ASEP) in registry. Adversaries may modify these keys to execute malicious code when Office files are opened. There are various legitimate add-ins that also use these keys and this filter list might not be exhaustive. Thus, it is recommended to review and tune filters for your environment to reduce false positives before deploying to production.
References:
  -https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1547.001/T1547.001.md
  -https://learn.microsoft.com/en-us/sysinternals/downloads/autoruns
  -https://gist.github.com/GlebSukhodolskiy/0fc5fa5f482903064b448890db1eaf9d
Author: Victor Sergeev, Daniil Yugoslavskiy, Gleb Sukhodolskiy, Timur Zinniatullin, oscd.community, Tim Shelton, frack113 (split)
Date: 2019-10-25
modified:2026-08-28
Tags:

• -'attack.privilege-escalation'
• -'attack.persistence'
• -'attack.t1547.001'

Logsource:

• category: registry_set
• product: windows

Detection:
  selection_office_root:
    TargetObject|contains:
      -'\Software\Wow6432Node\Microsoft\Office'
      -'\Software\Microsoft\Office'

  selection_office_details:
    TargetObject|contains:
      -'\Word\Addins'
      -'\PowerPoint\Addins'
      -'\Outlook\Addins'
      -'\Onenote\Addins'
      -'\Excel\Addins'
      -'\Access\Addins'
      -'test\Special\Perf'

  filter_main_empty:
    Details: '(Empty)'
  filter_main_null:
    Details: 'None'
  filter_main_known_addins:
    Image|startswith:
      -'C:\Program Files\Microsoft Office\'
      -'C:\Program Files (x86)\Microsoft Office\'
      -'C:\PROGRA~2\MICROS~2\Office'
      -'C:\Windows\System32\msiexec.exe'
      -'C:\Windows\SysWOW64\msiexec.exe'
      -'C:\Windows\System32\regsvr32.exe'
      -'C:\Windows\SysWOW64\regsvr32.exe'

    TargetObject|contains:
      -'\Excel\Addins\AdHocReportingExcelClientLib.AdHocReportingExcelClientAddIn.1\'
      -'\Excel\Addins\ExcelPlugInShell.PowerMapConnect\'
      -'\Excel\Addins\NativeShim\'
      -'\Excel\Addins\NativeShim.InquireConnector.1\'
      -'\Excel\Addins\PowerPivotExcelClientAddIn.NativeEntry.1\'
      -'\Outlook\AddIns\AccessAddin.DC\'
      -'\Outlook\AddIns\ColleagueImport.ColleagueImportAddin\'
      -'\Outlook\AddIns\EvernoteCC.EvernoteContactConnector\'
      -'\Outlook\AddIns\EvernoteOLRD.Connect\'
      -'\Outlook\Addins\OneNote.OutlookAddin'
      -'\Outlook\Addins\DriveFSExtensionLib.Connect\'
      -'\Outlook\Addins\GoogleAppsSync.Connect\'
      -'\Outlook\Addins\Microsoft.VbaAddinForOutlook.1\'
      -'\Outlook\Addins\OcOffice.OcForms\'
      -'\Outlook\Addins\OscAddin.Connect\'
      -'\Outlook\Addins\OutlookChangeNotifier.Connect\'
      -'\Outlook\Addins\UCAddin.LyncAddin.1'
      -'\Outlook\Addins\UCAddin.UCAddin.1'
      -'\Outlook\Addins\UmOutlookAddin.FormRegionAddin\'
      -'AddinTakeNotesService\FriendlyName'

  filter_main_officeclicktorun:
    Image|startswith:
      -'C:\Program Files\Common Files\Microsoft Shared\ClickToRun\'
      -'C:\Program Files\Common Files\Microsoft Shared\ClickToRun\Updates\'

    Image|endswith: '\OfficeClickToRun.exe'
  filter_main_vsto:
    Image|startswith:
      -'C:\Program Files\Common Files\Microsoft Shared\VSTO\'
      -'C:\Program Files (x86)\Microsoft Shared\VSTO\'

    Image|endswith: '\VSTOInstaller.exe'
  filter_optional_avg:
    Image:
      -'C:\Program Files\AVG\Antivirus\RegSvr.exe'
      -'C:\Program Files\AVG\Antivirus\x86\RegSvr.exe'

    TargetObject|contains: '\Microsoft\Office\Outlook\Addins\Antivirus.AsOutExt\'
  filter_optional_avast:
    Image:
      -'C:\Program Files\Avast Software\Avast\RegSvr.exe'
      -'C:\Program Files\Avast Software\Avast\x86\RegSvr.exe'

    TargetObject|contains: '\Microsoft\Office\Outlook\Addins\Avast.AsOutExt\'
  condition:all of selection_office_* and not 1 of filter_main_* and not 1 of filter_optional_*
Falsepositives:
  -Legitimate software or add-in installations and administrative configurations
  -Automatic registry modifications during legitimate software installations
Level: medium