Windows Office Product Spawned Uncommon Process

Description

The following analytic detects a Microsoft Office product spawning uncommon processes. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events where Office applications are the parent process. This activity is significant as it may indicate an attempt of a malicious macro execution or exploitation of an unknown vulnerability in an office product, in order to bypass security controls. If confirmed malicious, this behavior could allow an attacker to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.

Query · spl

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime from datamodel=Endpoint.Processes where
`process_office_products_parent`
AND
(
  Processes.process_name IN (
    bitsadmin.exe,
    certutil.exe,
    cmd.exe,
    cscript.exe,
    mshta.exe,
    powershell.exe,
    pwsh.exe,
    regsvr32.exe,
    rundll32.exe,
    wmic.exe,
    wscript.exe
  )
  OR
  Processes.original_file_name IN (
    bitsadmin.exe,
    CertUtil.exe,
    Cmd.Exe,
    cscript.exe,
    MSHTA.EXE,
    PowerShell.EXE,
    pwsh.dll,
    REGSVR32.EXE,
    RUNDLL32.EXE,
    wmic.exe,
    wscript.exe
  )
)
by Processes.action Processes.dest Processes.original_file_name
   Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
   Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
   Processes.process Processes.process_exec Processes.process_guid Processes.process_hash
   Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path
   Processes.user Processes.user_id Processes.vendor_product | `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_office_product_spawned_uncommon_process_filter`

Implementation guide

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known false positives

  • False positives should be limited, however filter as needed.

Analyst notes

Known false positives: False positives should be limited, however filter as needed.

Raw source Windows Office Product Spawned Uncommon Process · SPL
Esc
Published by splunk/security_content ↗, licensed under Apache 2.0 ↗. Reproduced here unmodified. 
name: Windows Office Product Spawned Uncommon Process
id: 55d8741c-fa32-4692-8109-410304961eb8
version: 9
creation_date: '2025-01-14'
modification_date: '2026-05-13'
author: Michael Haag, Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects a Microsoft Office product spawning uncommon processes. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events where Office applications are the parent process. This activity is significant as it may indicate an attempt of a malicious macro execution or exploitation of an unknown vulnerability in an office product, in order to bypass security controls. If confirmed malicious, this behavior could allow an attacker to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
    as lastTime from datamodel=Endpoint.Processes where
    `process_office_products_parent`
    AND
    (
      Processes.process_name IN (
        bitsadmin.exe,
        certutil.exe,
        cmd.exe,
        cscript.exe,
        mshta.exe,
        powershell.exe,
        pwsh.exe,
        regsvr32.exe,
        rundll32.exe,
        wmic.exe,
        wscript.exe
      )
      OR
      Processes.original_file_name IN (
        bitsadmin.exe,
        CertUtil.exe,
        Cmd.Exe,
        cscript.exe,
        MSHTA.EXE,
        PowerShell.EXE,
        pwsh.dll,
        REGSVR32.EXE,
        RUNDLL32.EXE,
        wmic.exe,
        wscript.exe
      )
    )
    by Processes.action Processes.dest Processes.original_file_name
       Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
       Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
       Processes.process Processes.process_exec Processes.process_guid Processes.process_hash
       Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path
       Processes.user Processes.user_id Processes.vendor_product | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_office_product_spawned_uncommon_process_filter`
how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: False positives should be limited, however filter as needed.
references:
    - https://any.run/malware-trends/trickbot
    - https://any.run/report/47561b4e949041eff0a0f4693c59c81726591779fe21183ae9185b5eb6a69847/aba3722a-b373-4dae-8273-8730fb40cdbe
    - https://app.any.run/tasks/fb894ab8-a966-4b72-920b-935f41756afd/
    - https://attack.mitre.org/techniques/T1047/
    - https://bazaar.abuse.ch/sample/02cbc1ab80695fc12ff8822b926957c3a600247b9ca412a137f69cb5716c8781/
    - https://blog.cluster25.duskrise.com/2022/09/23/in-the-footsteps-of-the-fancy-bear-powerpoint-graphite/
    - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1047/T1047.md
    - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1105/T1105.md
    - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1197/T1197.md
    - https://redcanary.com/threat-detection-report/threats/TA551/
    - https://twitter.com/cyb3rops/status/1416050325870587910?s=21
    - https://www.fortinet.com/blog/threat-research/latest-remcos-rat-phishing
    - https://www.joesandbox.com/analysis/380662/0/html
    - https://www.joesandbox.com/analysis/702680/0/html
    - https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/trojanized-onenote-document-leads-to-formbook-malware/
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: User $user$ on $dest$ spawned Windows Script Host from Winword.exe
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: User $user$ on $dest$ spawned Windows Script Host from Winword.exe
threat_objects:
    - field: process_name
      type: process_name
analytic_story:
    - AgentTesla
    - Azorult
    - Compromised Windows Host
    - CVE-2023-21716 Word RTF Heap Corruption
    - CVE-2023-36884 Office and Windows HTML RCE Vulnerability
    - DarkCrystal RAT
    - FIN7
    - IcedID
    - NjRAT
    - PlugX
    - Qakbot
    - Remcos
    - Spearphishing Attachments
    - Trickbot
    - Warzone RAT
    - APT37 Rustonotto and FadeStealer
    - MuddyWater
asset_type: Endpoint
mitre_attack_id:
    - T1566.001
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test - Macro
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.001/macro/windows-sysmon_macros.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.001/datasets/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit
    - name: True Positive Test - IcedId
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/icedid/phish_icedid/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566.002/atomic_red_team/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit
    - name: True Positive Test - TrickBot
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/trickbot/spear_phish/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

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