title: Suspicious Microsoft Office Child Process - MacOS
id: 69483748-1525-4a6c-95ca-90dc8d431b68
status: test
description: Detects suspicious child processes spawning from microsoft office suite applications such as word or excel. This could indicates malicious macro execution
references:
    - https://redcanary.com/blog/applescript/
    - https://objective-see.org/blog/blog_0x4B.html
author: Sohan G (D4rkCiph3r)
date: 2023-01-31
modified: 2023-02-04
tags:
    - attack.execution
    - attack.persistence
    - attack.t1059.002
    - attack.t1137.002
    - attack.t1204.002
logsource:
    product: macos
    category: process_creation
detection:
    selection:
        ParentImage|contains:
            - 'Microsoft Word'
            - 'Microsoft Excel'
            - 'Microsoft PowerPoint'
            - 'Microsoft OneNote'
        Image|endswith:
            - '/bash'
            - '/curl'
            - '/dash'
            - '/fish'
            - '/osacompile'
            - '/osascript'
            - '/sh'
            - '/zsh'
            - '/python'
            - '/python3'
            - '/wget'
    condition: selection
falsepositives:
    - Unknown
level: high

title: Code Executed Via Office Add-in XLL File
id: 36fbec91-fa1b-4d5d-8df1-8d8edcb632ad
status: test
description: |
    Adversaries may abuse Microsoft Office add-ins to obtain persistence on a compromised system.
    Office add-ins can be used to add functionality to Office programs
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1137.006/T1137.006.md
author: frack113
date: 2021-12-28
tags:
    - attack.persistence
    - attack.t1137.006
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains|all:
            - 'new-object '
            - '-ComObject '
            - '.application'
            - '.RegisterXLL'
    condition: selection
falsepositives:
    - Unknown
level: high

title: Potential Persistence Via Microsoft Office Add-In
id: 8e1cb247-6cf6-42fa-b440-3f27d57e9936
status: test
description: Detects potential persistence activity via startup add-ins that load when Microsoft Office starts (.wll/.xll are simply .dll fit for Word or Excel).
references:
    - Internal Research
    - https://labs.withsecure.com/publications/add-in-opportunities-for-office-persistence
    - https://github.com/redcanaryco/atomic-red-team/blob/4ae9580a1a8772db87a1b6cdb0d03e5af231e966/atomics/T1137.006/T1137.006.md
author: NVISO
date: 2020-05-11
modified: 2023-02-08
tags:
    - attack.persistence
    - attack.t1137.006
logsource:
    category: file_event
    product: windows
detection:
    selection_wlldropped:
        TargetFilename|contains: '\Microsoft\Word\Startup\'
        TargetFilename|endswith: '.wll'
    selection_xlldropped:
        TargetFilename|contains: '\Microsoft\Excel\Startup\'
        TargetFilename|endswith: '.xll'
    selection_xladropped:
        TargetFilename|contains: 'Microsoft\Excel\XLSTART\'
        TargetFilename|endswith: '.xlam'
    selection_generic:
        TargetFilename|contains: '\Microsoft\Addins\'
        TargetFilename|endswith:
            - '.xlam'
            - '.xla'
            - '.ppam'
    condition: 1 of selection_*
falsepositives:
    - Legitimate add-ins
level: high

title: Potential Persistence Via Microsoft Office Startup Folder
id: 0e20c89d-2264-44ae-8238-aeeaba609ece
status: test
description: Detects creation of Microsoft Office files inside of one of the default startup folders in order to achieve persistence.
references:
    - https://insight-jp.nttsecurity.com/post/102hojk/operation-restylink-apt-campaign-targeting-japanese-companies
    - https://learn.microsoft.com/en-us/office/troubleshoot/excel/use-startup-folders
author: Max Altgelt (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2022-06-02
modified: 2023-06-22
tags:
    - attack.persistence
    - attack.t1137
logsource:
    category: file_event
    product: windows
detection:
    selection_word_paths:
        - TargetFilename|contains: '\Microsoft\Word\STARTUP'
        - TargetFilename|contains|all:
              - '\Office'
              - '\Program Files'
              - '\STARTUP'
    selection_word_extension:
        TargetFilename|endswith:
            - '.doc'
            - '.docm'
            - '.docx'
            - '.dot'
            - '.dotm'
            - '.rtf'
    selection_excel_paths:
        - TargetFilename|contains: '\Microsoft\Excel\XLSTART'
        - TargetFilename|contains|all:
              - '\Office'
              - '\Program Files'
              - '\XLSTART'
    selection_excel_extension:
        TargetFilename|endswith:
            - '.xls'
            - '.xlsm'
            - '.xlsx'
            - '.xlt'
            - '.xltm'
    filter_main_office:
        Image|endswith:
            - '\WINWORD.exe'
            - '\EXCEL.exe'
    condition: (all of selection_word_* or all of selection_excel_*) and not filter_main_office
falsepositives:
    - Loading a user environment from a backup or a domain controller
    - Synchronization of templates
level: high

title: File With Uncommon Extension Created By An Office Application
id: c7a74c80-ba5a-486e-9974-ab9e682bc5e4
status: test
description: Detects the creation of files with an executable or script extension by an Office application.
references:
    - https://thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware/
    - https://github.com/vadim-hunter/Detection-Ideas-Rules/blob/02bcbfc2bfb8b4da601bb30de0344ae453aa1afe/Threat%20Intelligence/The%20DFIR%20Report/20210329_Sodinokibi_(aka_REvil)_Ransomware.yaml
author: Vadim Khrykov (ThreatIntel), Cyb3rEng (Rule), Nasreddine Bencherchali (Nextron Systems)
date: 2021-08-23
modified: 2025-10-17
tags:
    - attack.t1204.002
    - attack.execution
logsource:
    product: windows
    category: file_event
detection:
    # Note: Please add more file extensions to the logic of your choice.
    selection1:
        Image|endswith:
            - '\excel.exe'
            - '\msaccess.exe'
            - '\mspub.exe'
            - '\powerpnt.exe'
            - '\visio.exe'
            - '\winword.exe'
    selection2:
        TargetFilename|endswith:
            - '.bat'
            - '.cmd'
            - '.com'
            - '.dll'
            - '.exe'
            - '.hta'
            - '.ocx'
            - '.proj'
            - '.ps1'
            - '.scf'
            - '.scr'
            - '.sys'
            - '.vbe'
            - '.vbs'
            - '.wsf'
            - '.wsh'
    filter_main_localassembly:
        TargetFilename|contains: '\AppData\Local\assembly\tmp\'
        TargetFilename|endswith: '.dll'
    filter_optional_webservicecache: # matches e.g. directory with name *.microsoft.com
        TargetFilename|contains|all:
            - 'C:\Users\'
            - '\AppData\Local\Microsoft\Office\'
            - '\WebServiceCache\AllUsers'
        TargetFilename|endswith: '.com'
    filter_optional_webex:
        Image|endswith: '\winword.exe'
        TargetFilename|contains: '\AppData\Local\Temp\webexdelta\'
        TargetFilename|endswith:
            - '.dll'
            - '.exe'
    filter_optional_backstageinappnavcache: # matches e.g. C:\Users\xxxxx\AppData\Local\Microsoft\Office\16.0\BackstageInAppNavCache\ODB-user@domain.com
        TargetFilename|contains|all:
            - 'C:\Users\'
            - '\AppData\Local\Microsoft\Office\'
            - '\BackstageInAppNavCache\'
        TargetFilename|endswith: '.com'
    condition: all of selection* and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: high

title: Office Macro File Creation From Suspicious Process
id: b1c50487-1967-4315-a026-6491686d860e
status: test
description: Detects the creation of a office macro file from a a suspicious process
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1566.001/T1566.001.md
    - https://learn.microsoft.com/en-us/deployoffice/compat/office-file-format-reference
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2022-01-23
modified: 2023-02-22
tags:
    - attack.initial-access
    - attack.t1566.001
logsource:
    category: file_event
    product: windows
    definition: 'Requirements: The "ParentImage" field is not available by default on EID 11 of Sysmon logs. To be able to use this rule to the full extent you need to enriche the log with additional ParentImage data'
detection:
    selection_cmd:
        - Image|endswith:
              - '\cscript.exe'
              - '\mshta.exe'
              - '\regsvr32.exe'
              - '\rundll32.exe'
              - '\wscript.exe'
        # Note: ParentImage is a custom field and is not available by default on Sysmon EID 11
        - ParentImage|endswith:
              - '\cscript.exe'
              - '\mshta.exe'
              - '\regsvr32.exe'
              - '\rundll32.exe'
              - '\wscript.exe'
    selection_ext:
        TargetFilename|endswith:
            - '.docm'
            - '.dotm'
            - '.xlsm'
            - '.xltm'
            - '.potm'
            - '.pptm'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

title: Uncommon File Created In Office Startup Folder
id: a10a2c40-2c4d-49f8-b557-1a946bc55d9d
status: test
description: Detects the creation of a file with an uncommon extension in an Office application startup folder
references:
    - https://app.any.run/tasks/d6fe6624-6ef8-485d-aa75-3d1bdda2a08c/
    - http://addbalance.com/word/startup.htm
    - https://answers.microsoft.com/en-us/msoffice/forum/all/document-in-word-startup-folder-doesnt-open-when/44ab0932-2917-4150-8cdc-2f2cf39e86f3
    - https://en.wikipedia.org/wiki/List_of_Microsoft_Office_filename_extensions
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2022-06-05
modified: 2023-12-13
tags:
    - attack.resource-development
    - attack.t1587.001
logsource:
    product: windows
    category: file_event
detection:
    selection_word_paths:
        - TargetFilename|contains: '\Microsoft\Word\STARTUP'
        - TargetFilename|contains|all:
              - '\Office'
              - '\Program Files'
              - '\STARTUP'
    filter_exclude_word_ext:
        TargetFilename|endswith:
            - '.docb' # Word binary document introduced in Microsoft Office 2007
            - '.docm' # Word macro-enabled document; same as docx, but may contain macros and scripts
            - '.docx' # Word document
            - '.dotm' # Word macro-enabled template; same as dotx, but may contain macros and scripts
            - '.mdb' # MS Access DB
            - '.mdw' # MS Access DB
            - '.pdf' # PDF documents
            - '.wll' # Word add-in
            - '.wwl' # Word add-in
    selection_excel_paths:
        - TargetFilename|contains: '\Microsoft\Excel\XLSTART'
        - TargetFilename|contains|all:
              - '\Office'
              - '\Program Files'
              - '\XLSTART'
    filter_exclude_excel_ext:
        TargetFilename|endswith:
            - '.xll'
            - '.xls'
            - '.xlsm'
            - '.xlsx'
            - '.xlt'
            - '.xltm'
            - '.xlw'
    filter_main_office_click_to_run:
        Image|contains: ':\Program Files\Common Files\Microsoft Shared\ClickToRun\'
        Image|endswith: '\OfficeClickToRun.exe'
    filter_main_office_apps:
        Image|contains:
            - ':\Program Files\Microsoft Office\'
            - ':\Program Files (x86)\Microsoft Office\'
        Image|endswith:
            - '\winword.exe'
            - '\excel.exe'
    condition: ((selection_word_paths and not filter_exclude_word_ext) or (selection_excel_paths and not filter_exclude_excel_ext)) and not 1 of filter_main_*
falsepositives:
    - False positive might stem from rare extensions used by other Office utilities.
level: high

title: Potentially Suspicious Office Document Executed From Trusted Location
id: f99abdf0-6283-4e71-bd2b-b5c048a94743
status: test
description: Detects the execution of an Office application that points to a document that is located in a trusted location. Attackers often used this to avoid macro security and execute their malicious code.
references:
    - Internal Research
    - https://twitter.com/Max_Mal_/status/1633863678909874176
    - https://techcommunity.microsoft.com/t5/microsoft-365-blog/new-security-hardening-policies-for-trusted-documents/ba-p/3023465
    - https://twitter.com/_JohnHammond/status/1588155401752788994
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-06-21
modified: 2023-10-18
tags:
    - attack.stealth
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        # Note: we add a parent shell to reduce FP. Add additional 3rd party shells that you might use
        ParentImage|endswith:
            - '\explorer.exe'
            - '\dopus.exe'
    selection_img:
        - Image|endswith:
              - '\EXCEL.EXE'
              - '\POWERPNT.EXE'
              - '\WINWORD.exe'
        - OriginalFileName:
              - 'Excel.exe'
              - 'POWERPNT.EXE'
              - 'WinWord.exe'
    selection_trusted_location:
        CommandLine|contains:
            # Note: these are the default locations. Admins/Users could add additional ones that you need to cover
            - '\AppData\Roaming\Microsoft\Templates'
            - '\AppData\Roaming\Microsoft\Word\Startup\'
            - '\Microsoft Office\root\Templates\'
            - '\Microsoft Office\Templates\'
    filter_main_dotx:
        # Note: We add this filter to avoid curious people clicking on template files
        CommandLine|endswith:
            - '.dotx'
            - '.xltx'
            - '.potx'
    condition: all of selection_* and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high

title: Potential Arbitrary File Download Using Office Application
id: 4ae3e30b-b03f-43aa-87e3-b622f4048eed
related:
    - id: 0c79148b-118e-472b-bdb7-9b57b444cc19
      type: obsolete
status: test
description: Detects potential arbitrary file download using a Microsoft Office application
references:
    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Winword/
    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Powerpnt/
    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Excel/
    - https://medium.com/@reegun/unsanitized-file-validation-leads-to-malicious-payload-download-via-office-binaries-202d02db7191
author: Nasreddine Bencherchali (Nextron Systems), Beyu Denis, oscd.community
date: 2022-05-17
modified: 2023-06-22
tags:
    - attack.stealth
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith:
              - '\EXCEL.EXE'
              - '\POWERPNT.EXE'
              - '\WINWORD.exe'
        - OriginalFileName:
              - 'Excel.exe'
              - 'POWERPNT.EXE'
              - 'WinWord.exe'
    selection_http:
        CommandLine|contains:
            - 'http://'
            - 'https://'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

title: Suspicious Microsoft Office Child Process
id: 438025f9-5856-4663-83f7-52f878a70a50
related:
    - id: c27515df-97a9-4162-8a60-dc0eeb51b775 # Speicifc OneNote rule due to its recent usage in phishing attacks
      type: derived
    - id: e1693bc8-7168-4eab-8718-cdcaa68a1738
      type: derived
    - id: 23daeb52-e6eb-493c-8607-c4f0246cb7d8
      type: obsolete
    - id: 518643ba-7d9c-4fa5-9f37-baed36059f6a
      type: obsolete
    - id: 04f5363a-6bca-42ff-be70-0d28bf629ead
      type: obsolete
status: test
description: Detects a suspicious process spawning from one of the Microsoft Office suite products (Word, Excel, PowerPoint, Publisher, Visio, etc.)
references:
    - https://www.hybrid-analysis.com/sample/465aabe132ccb949e75b8ab9c5bda36d80cf2fd503d52b8bad54e295f28bbc21?environmentId=100
    - https://mgreen27.github.io/posts/2018/04/02/DownloadCradle.html
    - https://thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware/
    - https://doublepulsar.com/follina-a-microsoft-office-code-execution-vulnerability-1a47fce5629e
    - https://github.com/vadim-hunter/Detection-Ideas-Rules/blob/02bcbfc2bfb8b4da601bb30de0344ae453aa1afe/Threat%20Intelligence/The%20DFIR%20Report/20210329_Sodinokibi_(aka_REvil)_Ransomware.yaml
    - https://github.com/splunk/security_content/blob/300af51b88ad5d5b27ce4f5f54e4d6e6a3a2c06d/detections/endpoint/office_spawning_control.yml
    - https://twitter.com/andythevariable/status/1576953781581144064?s=20&t=QiJILvK4ZiBdR8RJe24u-A
    - https://www.elastic.co/security-labs/exploring-the-ref2731-intrusion-set
    - https://github.com/elastic/detection-rules/blob/c76a39796972ecde44cb1da6df47f1b6562c9770/rules/windows/defense_evasion_execution_msbuild_started_by_office_app.toml
    - https://www.vmray.com/analyses/2d2fa29185ad/report/overview.html
    - https://app.any.run/tasks/c903e9c8-0350-440c-8688-3881b556b8e0/
author: Florian Roth (Nextron Systems), Markus Neis, FPT.EagleEye Team, Vadim Khrykov, Cyb3rEng, Michael Haag, Christopher Peacock @securepeacock, @scythe_io
date: 2018-04-06
modified: 2023-04-24
tags:
    - attack.execution
    - attack.stealth
    - attack.t1047
    - attack.t1204.002
    - attack.t1218.010
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith:
            - '\EQNEDT32.EXE'
            - '\EXCEL.EXE'
            - '\MSACCESS.EXE'
            - '\MSPUB.exe'
            - '\ONENOTE.EXE'
            - '\POWERPNT.exe'
            - '\VISIO.exe'
            - '\WINWORD.EXE'
            - '\wordpad.exe'
            - '\wordview.exe'
    selection_child_processes:
        - OriginalFileName:
              - 'bitsadmin.exe'
              - 'CertOC.exe'
              - 'CertUtil.exe'
              - 'Cmd.Exe'
              - 'CMSTP.EXE'
              - 'cscript.exe'
              - 'curl.exe'
              - 'HH.exe'
              - 'IEExec.exe'
              - 'InstallUtil.exe'
              - 'javaw.exe'
              - 'Microsoft.Workflow.Compiler.exe'
              - 'msdt.exe'
              - 'MSHTA.EXE'
              - 'msiexec.exe'
              - 'Msxsl.exe'
              - 'odbcconf.exe'
              - 'pcalua.exe'
              - 'PowerShell.EXE'
              - 'RegAsm.exe'
              - 'RegSvcs.exe'
              - 'REGSVR32.exe'
              - 'RUNDLL32.exe'
              - 'schtasks.exe'
              - 'ScriptRunner.exe'
              - 'wmic.exe'
              - 'WorkFolders.exe'
              - 'wscript.exe'
        - Image|endswith:
              - '\AppVLP.exe'
              - '\bash.exe'
              - '\bitsadmin.exe'
              - '\certoc.exe'
              - '\certutil.exe'
              - '\cmd.exe'
              - '\cmstp.exe'
              - '\control.exe'
              - '\cscript.exe'
              - '\curl.exe'
              - '\forfiles.exe'
              - '\hh.exe'
              - '\ieexec.exe'
              - '\installutil.exe'
              - '\javaw.exe'
              - '\mftrace.exe'
              - '\Microsoft.Workflow.Compiler.exe'
              - '\msbuild.exe'
              - '\msdt.exe'
              - '\mshta.exe'
              - '\msidb.exe'
              - '\msiexec.exe'
              - '\msxsl.exe'
              - '\odbcconf.exe'
              - '\pcalua.exe'
              - '\powershell.exe'
              - '\pwsh.exe'
              - '\regasm.exe'
              - '\regsvcs.exe'
              - '\regsvr32.exe'
              - '\rundll32.exe'
              - '\schtasks.exe'
              - '\scrcons.exe'
              - '\scriptrunner.exe'
              - '\sh.exe'
              - '\svchost.exe'
              - '\verclsid.exe'
              - '\wmic.exe'
              - '\workfolders.exe'
              - '\wscript.exe'
    selection_child_susp_paths: # Idea: Laiali Kazalbach, Mohamed Elsayed (#4142)
        Image|contains:
            - '\AppData\'
            - '\Users\Public\'
            - '\ProgramData\'
            - '\Windows\Tasks\'
            - '\Windows\Temp\'
            - '\Windows\System32\Tasks\'
    condition: selection_parent and 1 of selection_child_*
falsepositives:
    - Unknown
level: high

title: Suspicious Binary In User Directory Spawned From Office Application
id: aa3a6f94-890e-4e22-b634-ffdfd54792cc
status: test
description: Detects an executable in the users directory started from one of the Microsoft Office suite applications (Word, Excel, PowerPoint, Publisher, Visio)
references:
    - https://blog.morphisec.com/fin7-not-finished-morphisec-spots-new-campaign
    - https://www.virustotal.com/gui/file/23160972c6ae07f740800fa28e421a81d7c0ca5d5cab95bc082b4a986fbac57
author: Jason Lynch
date: 2019-04-02
modified: 2023-02-04
tags:
    - attack.execution
    - attack.t1204.002
    - attack.g0046
    - car.2013-05-002
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith:
            - '\WINWORD.EXE'
            - '\EXCEL.EXE'
            - '\POWERPNT.exe'
            - '\MSPUB.exe'
            - '\VISIO.exe'
            - '\MSACCESS.exe'
            - '\EQNEDT32.exe'
            # - '\OUTLOOK.EXE' too many FPs
        Image|startswith: 'C:\users\'
        Image|endswith: '.exe'
    filter:
        Image|endswith: '\Teams.exe'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

title: Suspicious Download from Office Domain
id: 00d49ed5-4491-4271-a8db-650a4ef6f8c1
status: test
description: Detects suspicious ways to download files from Microsoft domains that are used to store attachments in Emails or OneNote documents
references:
    - https://twitter.com/an0n_r0/status/1474698356635193346?s=12
    - https://twitter.com/mrd0x/status/1475085452784844803?s=12
author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2021-12-27
modified: 2022-08-02
tags:
    - attack.command-and-control
    - attack.resource-development
    - attack.t1105
    - attack.t1608
logsource:
    product: windows
    category: process_creation
detection:
    selection_download:
        - Image|endswith:
              - '\curl.exe'
              - '\wget.exe'
        - CommandLine|contains:
              - 'Invoke-WebRequest'
              - 'iwr '
              - 'curl '
              - 'wget '
              - 'Start-BitsTransfer'
              - '.DownloadFile('
              - '.DownloadString('
    selection_domains:
        CommandLine|contains:
            - 'https://attachment.outlook.live.net/owa/'
            - 'https://onenoteonlinesync.onenote.com/onenoteonlinesync/'
    condition: all of selection_*
falsepositives:
    - Scripts or tools that download attachments from these domains (OneNote, Outlook 365)
level: high

title: Suspicious WMIC Execution Via Office Process
id: e1693bc8-7168-4eab-8718-cdcaa68a1738
related:
    - id: 438025f9-5856-4663-83f7-52f878a70a50
      type: derived
    - id: 518643ba-7d9c-4fa5-9f37-baed36059f6a
      type: obsolete
    - id: 9d1c72f5-43f0-4da5-9320-648cf2099dd0
      type: obsolete
    - id: c0e1c3d5-4381-4f18-8145-2583f06a1fe5
      type: obsolete
    - id: 04f5363a-6bca-42ff-be70-0d28bf629ead
      type: obsolete
status: test
description: Office application called wmic to proxye execution through a LOLBIN process. This is often used to break suspicious parent-child chain (Office app spawns LOLBin).
references:
    - https://thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware/
    - https://github.com/vadim-hunter/Detection-Ideas-Rules/blob/02bcbfc2bfb8b4da601bb30de0344ae453aa1afe/Threat%20Intelligence/The%20DFIR%20Report/20210329_Sodinokibi_(aka_REvil)_Ransomware.yaml
author: Vadim Khrykov, Cyb3rEng
date: 2021-08-23
modified: 2023-02-14
tags:
    - attack.stealth
    - attack.t1204.002
    - attack.t1047
    - attack.t1218.010
    - attack.execution
logsource:
    product: windows
    category: process_creation
detection:
    selection_parent:
        ParentImage|endswith:
            - '\WINWORD.EXE'
            - '\EXCEL.EXE'
            - '\POWERPNT.exe'
            - '\MSPUB.exe'
            - '\VISIO.exe'
            - '\MSACCESS.EXE'
            - '\EQNEDT32.EXE'
            - '\ONENOTE.EXE'
            - '\wordpad.exe'
            - '\wordview.exe'
    selection_wmic_img:
        - Image|endswith: '\wbem\WMIC.exe'
        - OriginalFileName: 'wmic.exe'
    selection_wmic_cli:
        CommandLine|contains|all:
            - 'process'
            - 'create'
            - 'call'
        CommandLine|contains:
            # Add more suspicious LOLBINs as you see fit
            - 'regsvr32'
            - 'rundll32'
            - 'msiexec'
            - 'mshta'
            - 'verclsid'
            - 'wscript'
            - 'cscript'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

title: Renamed Office Binary Execution
id: 0b0cd537-fc77-4e6e-a973-e53495c1083d
status: test
description: Detects the execution of a renamed office binary
references:
    - https://infosec.exchange/@sbousseaden/109542254124022664
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-12-20
modified: 2025-12-09
tags:
    - attack.stealth
    - attack.t1036.003
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - OriginalFileName:
              - 'Excel.exe'
              - 'MSACCESS.EXE'
              - 'MSPUB.EXE'
              - 'OneNote.exe'
              - 'OneNoteM.exe'
              - 'OUTLOOK.EXE'
              - 'POWERPNT.EXE'
              - 'WinWord.exe'
              - 'Olk.exe'
        - Description:
              - 'Microsoft Access'
              - 'Microsoft Excel'
              - 'Microsoft OneNote'
              - 'Microsoft Outlook'
              - 'Microsoft PowerPoint'
              - 'Microsoft Publisher'
              - 'Microsoft Word'
              - 'Sent to OneNote Tool'
    filter_main_legit_names:
        Image|endswith:
            - '\EXCEL.exe'
            - '\excelcnv.exe'
            - '\MSACCESS.exe'
            - '\MSPUB.EXE'
            - '\ONENOTE.EXE'
            - '\ONENOTEM.EXE'
            - '\OUTLOOK.EXE'
            - '\POWERPNT.EXE'
            - '\WINWORD.exe'
            - '\OLK.EXE'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high

title: Microsoft Office DLL Sideload
id: 829a3bdf-34da-4051-9cf4-8ed221a8ae4f
status: test
description: Detects DLL sideloading of DLLs that are part of Microsoft Office from non standard location
references:
    - https://hijacklibs.net/ # For list of DLLs that could be sideloaded (search for dlls mentioned here in there)
author: Nasreddine Bencherchali (Nextron Systems), Wietze Beukema (project and research)
date: 2022-08-17
modified: 2023-03-15
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\outllib.dll'
    filter:
        ImageLoaded|startswith:
            - 'C:\Program Files\Microsoft Office\OFFICE'
            - 'C:\Program Files (x86)\Microsoft Office\OFFICE'
            - 'C:\Program Files\Microsoft Office\Root\OFFICE'
            - 'C:\Program Files (x86)\Microsoft Office\Root\OFFICE'
    condition: selection and not filter
falsepositives:
    - Unlikely
level: high

title: VBA DLL Loaded Via Office Application
id: e6ce8457-68b1-485b-9bdd-3c2b5d679aa9
status: test
description: Detects VB DLL's loaded by an office application. Which could indicate the presence of VBA Macros.
references:
    - https://medium.com/threatpunter/detecting-adversary-tradecraft-with-image-load-event-logging-and-eql-8de93338c16
author: Antonlovesdnb
date: 2020-02-19
modified: 2023-02-10
tags:
    - attack.execution
    - attack.t1204.002
logsource:
    category: image_load
    product: windows
detection:
    selection:
        Image|endswith:
            - '\excel.exe'
            - '\mspub.exe'
            - '\onenote.exe'
            - '\onenoteim.exe' # Just in case
            - '\outlook.exe'
            - '\powerpnt.exe'
            - '\winword.exe'
        ImageLoaded|endswith:
            - '\VBE7.DLL'
            - '\VBEUI.DLL'
            - '\VBE7INTL.DLL'
    condition: selection
falsepositives:
    - Legitimate macro usage. Add the appropriate filter according to your environment
level: high

title: GAC DLL Loaded Via Office Applications
id: 90217a70-13fc-48e4-b3db-0d836c5824ac
status: test
description: Detects any GAC DLL being loaded by an Office Product
references:
    - https://medium.com/threatpunter/detecting-adversary-tradecraft-with-image-load-event-logging-and-eql-8de93338c16
author: Antonlovesdnb
date: 2020-02-19
modified: 2023-02-10
tags:
    - attack.execution
    - attack.t1204.002
logsource:
    category: image_load
    product: windows
detection:
    selection:
        Image|endswith:
            - '\excel.exe'
            - '\mspub.exe'
            - '\onenote.exe'
            - '\onenoteim.exe' # Just in case
            - '\outlook.exe'
            - '\powerpnt.exe'
            - '\winword.exe'
        ImageLoaded|startswith: 'C:\Windows\Microsoft.NET\assembly\GAC_MSIL'
    condition: selection
falsepositives:
    - Legitimate macro usage. Add the appropriate filter according to your environment
level: high

title: Office Macros Warning Disabled
id: 91239011-fe3c-4b54-9f24-15c86bb65913
related:
    - id: 9b894e57-033f-46cf-b7fa-a52804181973
      type: obsolete
status: test
description: Detects registry changes to Microsoft Office "VBAWarning" to a value of "1" which enables the execution of all macros, whether signed or unsigned.
references:
    - https://twitter.com/inversecos/status/1494174785621819397
    - https://www.mcafee.com/blogs/other-blogs/mcafee-labs/zloader-with-a-new-infection-technique/
    - https://securelist.com/scarcruft-surveilling-north-korean-defectors-and-human-rights-activists/105074/
author: Trent Liffick (@tliffick), Nasreddine Bencherchali (Nextron Systems)
date: 2020-05-22
modified: 2024-03-19
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|endswith: '\Security\VBAWarnings'
        Details: 'DWORD (0x00000001)'
    condition: selection
falsepositives:
    - Unlikely
level: high

title: Microsoft Office Protected View Disabled
id: a5c7a43f-6009-4a8c-80c5-32abf1c53ecc
related:
    - id: 7c637634-c95d-4bbf-b26c-a82510874b34
      type: obsolete
status: test
description: Detects changes to Microsoft Office protected view registry keys with which the attacker disables this feature.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.001/T1562.001.md
    - https://unit42.paloaltonetworks.com/unit42-gorgon-group-slithering-nation-state-cybercrime/
    - https://yoroi.company/research/cyber-criminal-espionage-operation-insists-on-italian-manufacturing/
    - https://admx.help/HKCU/software/policies/microsoft/office/16.0/excel/security/protectedview
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2021-06-08
modified: 2023-08-17
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    product: windows
    category: registry_set
detection:
    selection_path:
        TargetObject|contains|all:
            - '\SOFTWARE\Microsoft\Office\'
            - '\Security\ProtectedView\'
    selection_values_1:
        Details: 'DWORD (0x00000001)'
        TargetObject|endswith:
            - '\DisableAttachementsInPV' # Turn off Protected View for attachments opened from Outlook
            - '\DisableInternetFilesInPV' # Turn off Protected View for files downloaded from Internet zone
            - '\DisableIntranetCheck' # Turn off Protected View for file located in UNC paths
            - '\DisableUnsafeLocationsInPV' # Turn off Protected View for unsafe locations
    selection_values_0:
        Details: 'DWORD (0x00000000)'
        TargetObject|endswith:
            - '\enabledatabasefileprotectedview'
            - '\enableforeigntextfileprotectedview'
    condition: selection_path and 1 of selection_values_*
falsepositives:
    - Unlikely
level: high

title: Uncommon Microsoft Office Trusted Location Added
id: f742bde7-9528-42e5-bd82-84f51a8387d2
related:
    - id: a0bed973-45fa-4625-adb5-6ecdf9be70ac
      type: derived
status: test
description: Detects changes to registry keys related to "Trusted Location" of Microsoft Office where the path is set to something uncommon. Attackers might add additional trusted locations to avoid macro security restrictions.
references:
    - Internal Research
    - https://admx.help/?Category=Office2016&Policy=excel16.Office.Microsoft.Policies.Windows::L_TrustedLoc01
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-06-21
modified: 2023-09-29
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: 'Security\Trusted Locations\Location'
        TargetObject|endswith: '\Path'
    filter_exclude_known_paths:
        Details|contains:
            - '%APPDATA%\Microsoft\Templates'
            - '%%APPDATA%%\Microsoft\Templates'
            - '%APPDATA%\Microsoft\Word\Startup'
            - '%%APPDATA%%\Microsoft\Word\Startup'
            - ':\Program Files (x86)\Microsoft Office\root\Templates\'
            - ':\Program Files\Microsoft Office (x86)\Templates'
            - ':\Program Files\Microsoft Office\root\Templates\'
            - ':\Program Files\Microsoft Office\Templates\'
    filter_main_office_click_to_run:
        Image|contains: ':\Program Files\Common Files\Microsoft Shared\ClickToRun\'
        Image|endswith: '\OfficeClickToRun.exe'
    filter_main_office_apps:
        Image|contains:
            - ':\Program Files\Microsoft Office\'
            - ':\Program Files (x86)\Microsoft Office\'
    condition: selection and not 1 of filter_main_* and not 1 of filter_exclude_*
falsepositives:
    - Other unknown legitimate or custom paths need to be filtered to avoid false positives
level: high

title: Office Application Initiated Network Connection To Non-Local IP
id: 75e33ce3-ae32-4dcc-9aa8-a2a3029d6f84
status: test
description: |
    Detects an office application (Word, Excel, PowerPoint)  that initiate a network connection to a non-private IP addresses.
    This rule aims to detect traffic similar to one seen exploited in CVE-2021-42292.
    This rule will require an initial baseline and tuning that is specific to your organization.
references:
    - https://corelight.com/blog/detecting-cve-2021-42292
    - https://learn.microsoft.com/de-de/microsoft-365/enterprise/urls-and-ip-address-ranges?view=o365-worldwide
author: Christopher Peacock '@securepeacock', SCYTHE '@scythe_io', Florian Roth (Nextron Systems), Tim Shelton, Nasreddine Bencherchali (Nextron Systems)
date: 2021-11-10
modified: 2025-10-17
tags:
    - attack.execution
    - attack.t1203
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Image|endswith:
            - '\excel.exe'
            - '\outlook.exe'
            - '\powerpnt.exe'
            - '\winword.exe'
            - '\wordview.exe'
        Initiated: 'true'
    filter_main_local_ranges:
        DestinationIp|cidr:
            - '127.0.0.0/8'
            - '10.0.0.0/8'
            - '172.16.0.0/12'
            - '192.168.0.0/16'
            - '169.254.0.0/16'
            - '::1/128'  # IPv6 loopback
            - 'fe80::/10'  # IPv6 link-local addresses
            - 'fc00::/7'  # IPv6 private addresses
    filter_main_msrange_generic:
        DestinationIp|cidr:
            - '2.16.56.0/23' # Akamai International B.V.
            - '2.17.248.0/21' # Akamai International B.V.
            - '13.107.240.0/21' # Microsoft Corporation
            - '20.184.0.0/13' # Microsoft Corporation
            - '23.61.224.0/20' # Akamai-AS
            - '20.192.0.0/10' # Microsoft Corporation
            - '23.72.0.0/13' # Akamai International B.V.
            - '23.3.88.0/22' # Akamai-AS
            - '23.216.132.0/22' # Akamai-AS
            - '40.76.0.0/14' # Microsoft Corporation
            - '51.10.0.0/15' # Microsoft Corporation
            - '51.103.0.0/16' # Microsoft Corporation
            - '51.104.0.0/15' # Microsoft Corporation
            - '51.142.136.0/22' # Microsoft Corporation - https://ipinfo.io/AS8075/51.140.0.0/14-51.142.136.0/22
            - '52.160.0.0/11' # Microsoft Corporation - https://ipinfo.io/AS8075/52.160.0.0/11
            - '95.101.96.0/21' # Akamai-As
            - '204.79.197.0/24' # Microsoft Corporation
    filter_main_msrange_exchange_1:
        # Exchange Online
        # "urls": [
        #       "outlook.cloud.microsoft",
        #       "outlook.office.com",
        #       "outlook.office365.com"
        # ]
        DestinationIp|cidr:
            - '13.107.4.0/22'
            - '13.107.6.152/31'
            - '13.107.18.10/31'
            - '13.107.42.0/23'
            - '13.107.128.0/22'
            - '23.35.224.0/20'
            - '23.53.40.0/22'
            - '23.103.160.0/20'
            - '23.216.76.0/22'
            - '40.96.0.0/13'
            - '40.104.0.0/15'
            - '52.96.0.0/14'
            - '131.253.33.215/32'
            - '132.245.0.0/16'
            - '150.171.32.0/22'
            - '204.79.197.215/32'
            - '2603:1006::/40'
            - '2603:1016::/36'
            - '2603:1026::/36'
            - '2603:1036::/36'
            - '2603:1046::/36'
            - '2603:1056::/36'
            - '2620:1ec:4::152/128'
            - '2620:1ec:4::153/128'
            - '2620:1ec:c::10/128'
            - '2620:1ec:c::11/128'
            - '2620:1ec:d::10/128'
            - '2620:1ec:d::11/128'
            - '2620:1ec:8f0::/46'
            - '2620:1ec:900::/46'
            - '2620:1ec:a92::152/128'
            - '2620:1ec:a92::153/128'
        DestinationPort:
            - 80
            - 443
    filter_main_msrange_exchange_2:
        # Exchange Online
        # "urls": [
        #       "outlook.office365.com",
        #       "smtp.office365.com"
        # ]
        DestinationIp|cidr:
            - '13.107.6.152/31'
            - '13.107.18.10/31'
            - '13.107.128.0/22'
            - '23.103.160.0/20'
            - '40.96.0.0/13'
            - '40.104.0.0/15'
            - '52.96.0.0/14'
            - '131.253.33.215/32'
            - '132.245.0.0/16'
            - '150.171.32.0/22'
            - '204.79.197.215/32'
            - '2603:1006::/40'
            - '2603:1016::/36'
            - '2603:1026::/36'
            - '2603:1036::/36'
            - '2603:1046::/36'
            - '2603:1056::/36'
            - '2620:1ec:4::152/128'
            - '2620:1ec:4::153/128'
            - '2620:1ec:c::10/128'
            - '2620:1ec:c::11/128'
            - '2620:1ec:d::10/128'
            - '2620:1ec:d::11/128'
            - '2620:1ec:8f0::/46'
            - '2620:1ec:900::/46'
            - '2620:1ec:a92::152/128'
            - '2620:1ec:a92::153/128'
        DestinationPort:
            - 143
            - 587
            - 993
            - 995
        Protocol: 'tcp'
    filter_main_msrange_exchange_3:
        # Exchange Online
        # "urls": [
        #       "*.protection.outlook.com"
        #  ]
        DestinationIp|cidr:
            - '40.92.0.0/15'
            - '40.107.0.0/16'
            - '52.100.0.0/14'
            - '52.238.78.88/32'
            - '104.47.0.0/17'
            - '2a01:111:f400::/48'
            - '2a01:111:f403::/48'
        DestinationPort: 443
    filter_main_msrange_exchange_4:
        # Exchange Online
        # "urls": [
        #       "*.mail.protection.outlook.com",
        #       "*.mx.microsoft"
        #  ]
        DestinationIp|cidr:
            - '40.92.0.0/15'
            - '40.107.0.0/16'
            - '52.100.0.0/14'
            - '52.238.78.88/32'
            - '104.47.0.0/17'
            - '2a01:111:f400::/48'
            - '2a01:111:f403::/48'
        DestinationPort: 25
    filter_main_msrange_sharepoint_1:
        # SharePoint Online and OneDrive for Business",
        # "urls": [
        #       "*.sharepoint.com"
        # ]
        DestinationIp|cidr:
            - '13.107.136.0/22'
            - '40.108.128.0/17'
            - '52.104.0.0/14'
            - '104.146.128.0/17'
            - '150.171.40.0/22'
            - '2603:1061:1300::/40'
            - '2620:1ec:8f8::/46'
            - '2620:1ec:908::/46'
            - '2a01:111:f402::/48'
        DestinationPort:
            - 80
            - 443
        Protocol: 'tcp'
    filter_main_msrange_office_1:
        # Microsoft 365 Common and Office Online",
        # "urls": [
        #       "*.officeapps.live.com",
        #       "*.online.office.com",
        #       "office.live.com",
        #       "office.com.akadns.net"
        # ],
        DestinationIp|cidr:
            - '13.107.6.171/32'
            - '13.107.18.15/32'
            - '13.107.140.6/32'
            - '20.64.0.0/10'
            - '52.108.0.0/14'
            - '52.244.37.168/32'
            - '2603:1006:1400::/40'
            - '2603:1016:2400::/40'
            - '2603:1026:2400::/40'
            - '2603:1036:2400::/40'
            - '2603:1046:1400::/40'
            - '2603:1056:1400::/40'
            - '2603:1063:2000::/38'
            - '2620:1ec:c::15/128'
            - '2620:1ec:8fc::6/128'
            - '2620:1ec:a92::171/128'
            - '2a01:111:f100:2000::a83e:3019/128'
            - '2a01:111:f100:2002::8975:2d79/128'
            - '2a01:111:f100:2002::8975:2da8/128'
            - '2a01:111:f100:7000::6fdd:6cd5/128'
            - '2a01:111:f100:a004::bfeb:88cf/128'
        DestinationPort:
            - 80
            - 443
        Protocol: 'tcp'
    filter_main_msrange_office_2:
        # Microsoft 365 Common and Office Online
        # "urls": [
        #       "*.auth.microsoft.com",
        #       "*.msftidentity.com",
        #       "*.msidentity.com",
        #       "account.activedirectory.windowsazure.com",
        #       "accounts.accesscontrol.windows.net",
        #       "adminwebservice.microsoftonline.com",
        #       "api.passwordreset.microsoftonline.com",
        #       "autologon.microsoftazuread-sso.com",
        #       "becws.microsoftonline.com",
        #       "ccs.login.microsoftonline.com",
        #       "clientconfig.microsoftonline-p.net",
        #       "cloudapp.azure.com",
        #       "companymanager.microsoftonline.com",
        #       "device.login.microsoftonline.com",
        #       "graph.microsoft.com",
        #       "graph.windows.net",
        #       "login-us.microsoftonline.com",
        #       "login.microsoft.com",
        #       "login.microsoftonline-p.com",
        #       "login.microsoftonline.com",
        #       "login.windows.net",
        #       "logincert.microsoftonline.com",
        #       "loginex.microsoftonline.com",
        #       "nexus.microsoftonline-p.com",
        #       "passwordreset.microsoftonline.com",
        #       "provisioningapi.microsoftonline.com",
        #       "web.core.windows.net",
        # ]
        DestinationIp|cidr:
            - '172.128.0.0/10'
            - '20.20.32.0/19'
            - '20.103.156.88/32' # msn.com
            - '20.190.128.0/18'
            - '20.231.128.0/19'
            - '40.126.0.0/18'
            - '57.150.0.0/15'
            - '2603:1006:2000::/48'
            - '2603:1007:200::/48'
            - '2603:1016:1400::/48'
            - '2603:1017::/48'
            - '2603:1026:3000::/48'
            - '2603:1027:1::/48'
            - '2603:1036:3000::/48'
            - '2603:1037:1::/48'
            - '2603:1046:2000::/48'
            - '2603:1047:1::/48'
            - '2603:1056:2000::/48'
            - '2603:1057:2::/48'
        DestinationPort:
            - 80
            - 443
        Protocol: 'tcp'
    filter_main_msrange_office_3:
        # Microsoft 365 Common and Office Online
        #  "urls": [
        #       "*.compliance.microsoft.com",
        #       "*.data.microsoft.com",
        #       "*.protection.office.com",
        #       "*.security.microsoft.com",
        #       "compliance.microsoft.com",
        #       "defender.microsoft.com",
        #       "protection.office.com",
        #       "security.microsoft.com",
        #       "teams.microsoft.com",
        #  ]
        DestinationIp|cidr:
            - '13.64.0.0/11'
            - '13.107.6.192/32'
            - '13.107.9.192/32'
            - '13.89.179.14/32'
            - '20.40.0.0/14'
            - '20.48.0.0/12'
            - '20.64.0.0/12'
            - '52.123.0.0/16'
            - '52.108.0.0/14'
            - '52.136.0.0/13'
            - '57.150.0.0/15'
            - '80.239.150.67/32' # Arelion Sweden AB
            - '2620:1ec:4::192/128'
            - '2620:1ec:a92::192/128'
        DestinationPort: 443
        Protocol: 'tcp'
    filter_main_destination_host:
        DestinationHostname|endswith: '.deploy.static.akamaitechnologies.com'
        DestinationPort: 443
        Protocol: 'tcp'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - You may have to tune certain domains out that Excel may call out to, such as microsoft or other business use case domains.
    - Office documents commonly have templates that refer to external addresses, like "sharepoint.ourcompany.com" may have to be tuned.
    - It is highly recommended to baseline your activity and tune out common business use cases.
level: medium

title: Office Application Initiated Network Connection Over Uncommon Ports
id: 3b5ba899-9842-4bc2-acc2-12308498bf42
status: test
description: Detects an office suit application (Word, Excel, PowerPoint, Outlook) communicating to target systems over uncommon ports.
references:
    - https://blogs.blackberry.com/en/2023/07/romcom-targets-ukraine-nato-membership-talks-at-nato-summit
author: X__Junior (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2023-07-12
modified: 2025-10-17
tags:
    - attack.command-and-control
    - attack.stealth
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        Image|endswith:
            - '\excel.exe'
            - '\outlook.exe'
            - '\powerpnt.exe'
            - '\winword.exe'
            - '\wordview.exe'
    filter_main_common_ports:
        DestinationPort:
            - 53 # DNS
            - 80 # HTTP
            - 139 # NETBIOS
            - 389 # LDAP
            - 443 # HTTPS
            - 445 # SMB
            - 3268 # MSFT-GC
    filter_main_outlook_ports:
        Image|contains: ':\Program Files\Microsoft Office\'
        Image|endswith: '\OUTLOOK.EXE'
        DestinationPort:
            - 143
            - 465 # SMTP
            - 587 # SMTP
            - 993 # IMAP
            - 995 # POP3
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Other ports can be used, apply additional filters accordingly
level: medium

title: PowerShell Core DLL Loaded Via Office Application
id: bb2ba6fb-95d4-4a25-89fc-30bb736c021a
status: test
description: Detects PowerShell core DLL being loaded by an Office Product
references:
    - Internal Research
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-06-01
tags:
    - attack.stealth
logsource:
    category: image_load
    product: windows
detection:
    selection:
        Image|endswith:
            - '\excel.exe'
            - '\mspub.exe'
            - '\outlook.exe'
            - '\onenote.exe'
            - '\onenoteim.exe' # Just in case
            - '\powerpnt.exe'
            - '\winword.exe'
        ImageLoaded|contains:
            - '\System.Management.Automation.Dll'
            - '\System.Management.Automation.ni.Dll'
    condition: selection
falsepositives:
    - Unknown
level: medium

title: DotNET Assembly DLL Loaded Via Office Application
id: ff0f2b05-09db-4095-b96d-1b75ca24894a
status: test
description: Detects any assembly DLL being loaded by an Office Product
references:
    - https://medium.com/threatpunter/detecting-adversary-tradecraft-with-image-load-event-logging-and-eql-8de93338c16
author: Antonlovesdnb
date: 2020-02-19
modified: 2023-03-29
tags:
    - attack.execution
    - attack.t1204.002
logsource:
    category: image_load
    product: windows
detection:
    selection:
        Image|endswith:
            - '\excel.exe'
            - '\mspub.exe'
            - '\onenote.exe'
            - '\onenoteim.exe' # Just in case
            - '\outlook.exe'
            - '\powerpnt.exe'
            - '\winword.exe'
        ImageLoaded|startswith: 'C:\Windows\assembly\'
    condition: selection
falsepositives:
    - Unknown
level: medium

title: CLR DLL Loaded Via Office Applications
id: d13c43f0-f66b-4279-8b2c-5912077c1780
status: test
description: Detects CLR DLL being loaded by an Office Product
references:
    - https://medium.com/threatpunter/detecting-adversary-tradecraft-with-image-load-event-logging-and-eql-8de93338c16
author: Antonlovesdnb
date: 2020-02-19
modified: 2023-03-29
tags:
    - attack.execution
    - attack.t1204.002
logsource:
    category: image_load
    product: windows
detection:
    selection:
        Image|endswith:
            - '\excel.exe'
            - '\mspub.exe'
            - '\outlook.exe'
            - '\onenote.exe'
            - '\onenoteim.exe' # Just in case
            - '\powerpnt.exe'
            - '\winword.exe'
        ImageLoaded|contains: '\clr.dll'
    condition: selection
falsepositives:
    - Unknown
level: medium

title: Potential Persistence Via Visual Studio Tools for Office
id: 9d15044a-7cfe-4d23-8085-6ebc11df7685
status: test
description: Detects persistence via Visual Studio Tools for Office (VSTO) add-ins in Office applications.
references:
    - https://twitter.com/_vivami/status/1347925307643355138
    - https://vanmieghem.io/stealth-outlook-persistence/
author: Bhabesh Raj
date: 2021-01-10
modified: 2026-01-09
tags:
    - attack.t1137.006
    - attack.persistence
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains:
            - '\Software\Microsoft\Office\Outlook\Addins\'
            - '\Software\Microsoft\Office\Word\Addins\'
            - '\Software\Microsoft\Office\Excel\Addins\'
            - '\Software\Microsoft\Office\Powerpoint\Addins\'
            - '\Software\Microsoft\VSTO\Security\Inclusion\'
    filter_main_system:
        Image:
            - 'C:\Windows\System32\msiexec.exe'
            - 'C:\Windows\SysWOW64\msiexec.exe'
            - 'C:\Windows\System32\regsvr32.exe'
            - 'C:\Windows\SysWOW64\regsvr32.exe' # e.g. default Evernote installation
    filter_main_office_click_to_run:
        Image|startswith:
            - 'C:\Program Files\Common Files (x86)\Microsoft Shared\ClickToRun\'
            - 'C:\Program Files\Common Files\Microsoft Shared\ClickToRun\'
        Image|endswith: '\OfficeClickToRun.exe'
    filter_main_integrator:
        Image:
            - 'C:\Program Files (x86)\Microsoft Office\root\integration\integrator.exe'
            - 'C:\Program Files\Microsoft Office\root\integration\integrator.exe'
    filter_main_office_apps:
        Image|startswith:
            - 'C:\Program Files\Microsoft Office\OFFICE'
            - 'C:\Program Files (x86)\Microsoft Office\OFFICE'
            - 'C:\Program Files\Microsoft Office\Root\OFFICE'
            - 'C:\Program Files (x86)\Microsoft Office\Root\OFFICE'
            - 'C:\PROGRA~2\MICROS~2\Office'
        Image|endswith:
            - '\excel.exe'
            - '\Integrator.exe'
            - '\OneNote.exe'
            - '\outlook.exe'
            - '\powerpnt.exe'
            - '\Teams.exe'
            - '\visio.exe'
            - '\winword.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 (x86)\AVG\Antivirus\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 (x86)\Avast Software\Avast\RegSvr.exe'
        TargetObject|contains: '\Microsoft\Office\Outlook\Addins\Avast.AsOutExt\'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Legitimate Addin Installation
level: medium

title: Office Autorun Keys Modification
id: baecf8fb-edbf-429f-9ade-31fc3f22b970
related:
    - id: 17f878b8-9968-4578-b814-c4217fc5768c
      type: obsolete
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 # a list with registry keys
author: Victor Sergeev, Daniil Yugoslavskiy, Gleb Sukhodolskiy, Timur Zinniatullin, oscd.community, Tim Shelton, frack113 (split)
date: 2019-10-25
modified: 2026-01-09
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: null
    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:
            # Remove any unused addins in your environment from the filter
            # Known addins for excel
            - '\Excel\Addins\AdHocReportingExcelClientLib.AdHocReportingExcelClientAddIn.1\'
            - '\Excel\Addins\ExcelPlugInShell.PowerMapConnect\'
            - '\Excel\Addins\NativeShim\'
            - '\Excel\Addins\NativeShim.InquireConnector.1\'
            - '\Excel\Addins\PowerPivotExcelClientAddIn.NativeEntry.1\'
            # Known addins for outlook
            - '\Outlook\AddIns\AccessAddin.DC\'
            - '\Outlook\AddIns\ColleagueImport.ColleagueImportAddin\'
            - '\Outlook\AddIns\EvernoteCC.EvernoteContactConnector\'
            - '\Outlook\AddIns\EvernoteOLRD.Connect\'
            # - '\Outlook\Addins\GrammarlyAddIn.Connect' # Uncomment if you use Grammarly
            - '\Outlook\Addins\\OneNote.OutlookAddin'
            - '\Outlook\Addins\DriveFSExtensionLib.Connect\' # An Outlook Add-in to talk with Google Drive
            - '\Outlook\Addins\GoogleAppsSync.Connect\' # Google Apps Sync for Microsoft Outlook
            - '\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\'
    # These filters are not exhaustive, filter can be expanded based on environment
    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

title: Office Application Startup - Office Test
id: 3d27f6dd-1c74-4687-b4fa-ca849d128d1c
status: test
description: Detects the addition of office test registry that allows a user to specify an arbitrary DLL that will be executed every time an Office application is started
references:
    - https://unit42.paloaltonetworks.com/unit42-technical-walkthrough-office-test-persistence-method-used-in-recent-sofacy-attacks/
author: omkar72
date: 2020-10-25
modified: 2023-11-08
tags:
    - attack.persistence
    - attack.t1137.002
logsource:
    category: registry_event
    product: windows
detection:
    selection:
        TargetObject|contains: '\Software\Microsoft\Office test\Special\Perf'
    condition: selection
falsepositives:
    - Unlikely
level: medium

title: Office Macro File Creation
id: 91174a41-dc8f-401b-be89-7bfc140612a0
related:
    - id: 0e29e3a7-1ad8-40aa-b691-9f82ecd33d66
      type: similar
status: test
description: Detects the creation of a new office macro files on the systems
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1566.001/T1566.001.md
    - https://learn.microsoft.com/en-us/deployoffice/compat/office-file-format-reference
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-01-23
modified: 2026-01-09
tags:
    - attack.initial-access
    - attack.t1566.001
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|endswith:
            - '.docm'
            - '.dotm'
            - '.xlsm'
            - '.xltm'
            - '.potm'
            - '.pptm'
    filter_main_office:
        Image|startswith:
            - 'C:\Program Files\Microsoft Office\'
            - 'C:\Program Files (x86)\Microsoft Office\'
        Image|endswith:
            - '\WINWORD.EXE'
            - '\EXCEL.EXE'
            - '\POWERPNT.EXE'
        TargetFilename|contains: '\~$' # Temporary files created by Office applications
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Very common in environments that rely heavily on macro documents
level: low

title: Office Macro File Download
id: 0e29e3a7-1ad8-40aa-b691-9f82ecd33d66
related:
    - id: 91174a41-dc8f-401b-be89-7bfc140612a0
      type: similar
status: test
description: |
    Detects the creation of a new office macro files on the system via an application (browser, mail client).
    This can help identify potential malicious activity, such as the download of macro-enabled documents that could be used for exploitation.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1566.001/T1566.001.md
    - https://learn.microsoft.com/en-us/deployoffice/compat/office-file-format-reference
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-01-23
modified: 2025-10-29
tags:
    - attack.initial-access
    - attack.t1566.001
logsource:
    category: file_event
    product: windows
detection:
    selection_processes:
        Image|endswith:
            # Email clients
            - '\RuntimeBroker.exe' # Windows Email clients uses RuntimeBroker to create the files
            - '\outlook.exe'
            - '\thunderbird.exe'
            # Browsers
            - '\brave.exe'
            - '\chrome.exe'
            - '\firefox.exe'
            - '\iexplore.exe'
            - '\maxthon.exe'
            - '\MicrosoftEdge.exe'
            - '\msedge.exe'
            - '\msedgewebview2.exe'
            - '\opera.exe'
            - '\safari.exe'
            - '\seamonkey.exe'
            - '\vivaldi.exe'
            - '\whale.exe'
    selection_ext:
        - TargetFilename|endswith:
              - '.docm'
              - '.dotm'
              - '.xlsm'
              - '.xltm'
              - '.potm'
              - '.pptm'
        - TargetFilename|contains:
              - '.docm:Zone'
              - '.dotm:Zone'
              - '.xlsm:Zone'
              - '.xltm:Zone'
              - '.potm:Zone'
              - '.pptm:Zone'
    condition: all of selection_*
falsepositives:
    - Legitimate macro files downloaded from the internet
    - Legitimate macro files sent as attachments via emails
level: low