Sigma rule: Suspicious Microsoft Office Child Process

Rule

Title

Suspicious Microsoft Office Child Process

Status

test

Level

high

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

File

rules/windows/process_creation/proc_creation_win_office_susp_child_processes.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a suspicious process spawning from one of the Microsoft Office suite products (Word, Excel, PowerPoint, Publisher, Visio, etc.)

Log source

product

windows

category

process_creation

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_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.stealth
• attack.t1047
• attack.t1204.002
• attack.t1218.010

MITRE ATT&CK ids this rule names

• T1047
• T1204.002
• T1218.010

Related rules

• c27515df-97a9-4162-8a60-dc0eeb51b775 (derived)
• e1693bc8-7168-4eab-8718-cdcaa68a1738 (derived)
• 23daeb52-e6eb-493c-8607-c4f0246cb7d8 (obsolete)
• 518643ba-7d9c-4fa5-9f37-baed36059f6a (obsolete)
• 04f5363a-6bca-42ff-be70-0d28bf629ead (obsolete)

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/

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/process_creation/proc_creation_win_office_susp_child_processes.yml