Windows Svchost.exe Parent Process Anomaly

name: Windows Svchost.exe Parent Process Anomaly
id: 1d38e5e9-2ff8-4c47-872c-bf1657cefab5
version: 6
date: '2026-03-10'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects an anomaly where an svchost.exe process is spawned by a parent process other than the standard services.exe. In a typical Windows environment, svchost.exe is a system process that hosts Windows service DLLs, and is expected to be a child of services.exe. A process deviation from this hierarchy may indicate suspicious behavior, such as malicious code attempting to masquerade as a legitimate system process or evade detection. It is essential to investigate the parent process and associated behavior for further signs of compromise or unauthorized activity.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name != "services.exe" AND Processes.process_name = "svchost.exe" AND Processes.process != unknown AND Processes.parent_process_path != "C:\\ProgramData\\Microsoft\\Windows Defender\\Platform\\*\\MsMpEng.exe" AND Processes.parent_process_path != "C:\\Program Files\\Windows Defender\\MsMpEng.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_svchost_exe_parent_process_anomaly_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: Windows Update or other Windows Installer processes may launch their own svchost.exe processes that are not directly spawned by services.exe in certain edge cases (e.g., during patches or updates).
references:
    - https://attack.mitre.org/techniques/T1036/009/
    - https://www.trendmicro.com/en_nl/research/24/k/earth-estries.html
drilldown_searches:
    - name: View the detection results for - "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168  | 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: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: An svchost.exe process was spawned by an unexpected parent process [$parent_process_name$] instead of services.exe on [$dest$].
    risk_objects:
        - field: dest
          type: system
          score: 20
        - field: user
          type: user
          score: 20
    threat_objects:
        - field: parent_process_name
          type: parent_process_name
tags:
    analytic_story:
        - SnappyBee
        - China-Nexus Threat Activity
    asset_type: Endpoint
    mitre_attack_id:
        - T1036.009
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1035.009/suspicious_spawn_svchost/susp_svchost_proc.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog