title: Microsoft VBA For Outlook Addin Loaded Via Outlook
id: 9a0b8719-cd3c-4f0a-90de-765a4cb3f5ed
status: test
description: Detects outlvba (Microsoft VBA for Outlook Addin) DLL being loaded by the outlook process
references:
    - https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=58
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-02-08
modified: 2024-03-12
tags:
    - attack.execution
    - attack.t1204.002
logsource:
    category: image_load
    product: windows
detection:
    selection:
        Image|endswith: '\outlook.exe'
        ImageLoaded|endswith: '\outlvba.dll'
    condition: selection
falsepositives:
    - Legitimate macro usage. Add the appropriate filter according to your environment
level: medium

title: Outlook Security Settings Updated - Registry
id: c3cefdf4-6703-4e1c-bad8-bf422fc5015a
related:
    - id: 6763c6c8-bd01-4687-bc8d-4fa52cf8ba08 # EnableUnsafeClientMailRules
      type: similar
status: test
description: Detects changes to the registry values related to outlook security settings
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1137/T1137.md
    - https://learn.microsoft.com/en-us/outlook/troubleshoot/security/information-about-email-security-settings
author: frack113
date: 2021-12-28
modified: 2026-01-09
tags:
    - attack.persistence
    - attack.t1137
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains|all:
            - '\SOFTWARE\Microsoft\Office\'
            - '\Outlook\Security\'
    filter_main_outlook:
        Image|startswith:
            - 'C:\Program Files\Microsoft Office\'
            - 'C:\Program Files (x86)\Microsoft Office\'
        Image|endswith: '\OUTLOOK.EXE'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Administrative activity
level: medium

title: Publisher Attachment File Dropped In Suspicious Location
id: 3d2a2d59-929c-4b78-8c1a-145dfe9e07b1
status: test
description: Detects creation of files with the ".pub" extension in suspicious or uncommon locations. This could be a sign of attackers abusing Publisher documents
references:
    - https://twitter.com/EmericNasi/status/1623224526220804098
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-02-08
tags:
    - attack.stealth
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|contains:
            - '\AppData\Local\Temp\'
            - '\Users\Public\'
            - '\Windows\Temp\'
            - 'C:\Temp\'
        TargetFilename|endswith: '.pub'
    condition: selection
falsepositives:
    - Legitimate usage of ".pub" files from those locations
level: medium

title: Suspicious File Created Via OneNote Application
id: fcc6d700-68d9-4241-9a1a-06874d621b06
status: test
description: Detects suspicious files created via the OneNote application. This could indicate a potential malicious ".one"/".onepkg" file was executed as seen being used in malware activity in the wild
references:
    - https://www.bleepingcomputer.com/news/security/hackers-now-use-microsoft-onenote-attachments-to-spread-malware/
    - https://blog.osarmor.com/319/onenote-attachment-delivers-asyncrat-malware/
    - https://twitter.com/MaD_c4t/status/1623414582382567424
    - https://labs.withsecure.com/publications/detecting-onenote-abuse
    - https://www.trustedsec.com/blog/new-attacks-old-tricks-how-onenote-malware-is-evolving/
    - https://app.any.run/tasks/17f2d378-6d11-4d6f-8340-954b04f35e83/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-02-09
modified: 2023-02-27
tags:
    - attack.stealth
logsource:
    category: file_event
    product: windows
detection:
    selection:
        Image|endswith:
            - '\onenote.exe'
            - '\onenotem.exe'
            - '\onenoteim.exe'
        TargetFilename|contains: '\AppData\Local\Temp\OneNote\'
        TargetFilename|endswith:
            # TODO: Add more suspicious extensions
            - '.bat'
            - '.chm'
            - '.cmd'
            - '.dll'
            - '.exe'
            - '.hta'
            - '.htm'
            - '.html'
            - '.js'
            - '.lnk'
            - '.ps1'
            - '.vbe'
            - '.vbs'
            - '.wsf'
    condition: selection
falsepositives:
    - False positives should be very low with the extensions list cited. Especially if you don't heavily utilize OneNote.
    - Occasional FPs might occur if OneNote is used internally to share different embedded documents
level: high

title: Suspicious Microsoft OneNote Child Process
id: c27515df-97a9-4162-8a60-dc0eeb51b775
related:
    - id: 438025f9-5856-4663-83f7-52f878a70a50 # Generic rule for suspicious office application child processes
      type: derived
status: test
description: Detects suspicious child processes of the Microsoft OneNote application. This may indicate an attempt to execute malicious embedded objects from a .one file.
references:
    - https://github.com/elastic/protections-artifacts/commit/746086721fd385d9f5c6647cada1788db4aea95f#diff-e34e43eb5666427602ddf488b2bf3b545bd9aae81af3e6f6c7949f9652abdf18
    - https://micahbabinski.medium.com/detecting-onenote-one-malware-delivery-407e9321ecf0
author: Tim Rauch (Nextron Systems), Nasreddine Bencherchali (Nextron Systems), Elastic (idea)
date: 2022-10-21
modified: 2023-02-10
tags:
    - attack.t1566
    - attack.t1566.001
    - attack.initial-access
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith: '\onenote.exe'
    selection_opt_img:
        - 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_opt_explorer:
        Image|endswith: '\explorer.exe'
        CommandLine|contains:
            - '.hta'
            - '.vb'
            - '.wsh'
            - '.js'
            - '.ps'
            - '.scr'
            - '.pif'
            - '.bat'
            - '.cmd'
    selection_opt_paths:
        Image|contains:
            - '\AppData\'
            - '\Users\Public\'
            - '\ProgramData\'
            - '\Windows\Tasks\'
            - '\Windows\Temp\'
            - '\Windows\System32\Tasks\'
    filter_teams:
        Image|endswith: '\AppData\Local\Microsoft\Teams\current\Teams.exe'
        CommandLine|endswith: '-Embedding'
    filter_onedrive:
        Image|contains: '\AppData\Local\Microsoft\OneDrive\'
        Image|endswith: '\FileCoAuth.exe'
        CommandLine|endswith: '-Embedding'
    condition: selection_parent and 1 of selection_opt_* and not 1 of filter_*
falsepositives:
    - File located in the AppData folder with trusted signature
level: high

title: OneNote.EXE Execution of Malicious Embedded Scripts
id: 84b1706c-932a-44c4-ae28-892b28a25b94
status: test
description: |
    Detects the execution of malicious OneNote documents that contain embedded scripts.
    When a user clicks on a OneNote attachment and then on the malicious link inside the ".one" file, it exports and executes the malicious embedded script from specific directories.
references:
    - https://bazaar.abuse.ch/browse/tag/one/
author: '@kostastsale'
date: 2023-02-02
tags:
    - attack.stealth
    - attack.t1218.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\onenote.exe'
        Image|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\mshta.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\wscript.exe'
        CommandLine|contains:
            - '\exported\'
            - '\onenoteofflinecache_files\'
    condition: selection
falsepositives:
    - Unlikely
level: high

title: OneNote Attachment File Dropped In Suspicious Location
id: 7fd164ba-126a-4d9c-9392-0d4f7c243df0
status: test
description: Detects creation of files with the ".one"/".onepkg" extension in suspicious or uncommon locations. This could be a sign of attackers abusing OneNote attachments
references:
    - https://www.bleepingcomputer.com/news/security/hackers-now-use-microsoft-onenote-attachments-to-spread-malware/
    - https://blog.osarmor.com/319/onenote-attachment-delivers-asyncrat-malware/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-01-22
modified: 2023-09-19
tags:
    - attack.stealth
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|contains:
            # Note: add more common locations for drops such as download folders and the like. Or baseline legitimate locations and alert on everything else
            - '\AppData\Local\Temp\'
            - '\Users\Public\'
            - '\Windows\Temp\'
            - ':\Temp\'
        TargetFilename|endswith:
            - '.one'
            - '.onepkg'
    filter_main_onenote:
        Image|contains: ':\Program Files\Microsoft Office\'
        Image|endswith: '\ONENOTE.EXE'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate usage of ".one" or ".onepkg" files from those locations
level: medium