Svchost LOLBAS Execution Process Spawn

name: Svchost LOLBAS Execution Process Spawn
id: 09e5c72a-4c0d-11ec-aa29-3e22fbd008af
version: 15
creation_date: '2021-11-23'
modification_date: '2026-07-27'
author: Mauricio Velazco, Splunk
status: production
type: TTP
description: |-
    The following analytic detects instances of 'svchost.exe' spawning Living Off The Land Binaries and Scripts (LOLBAS) processes. It leverages Endpoint Detection and Response (EDR) data to monitor child processes of 'svchost.exe' that match known LOLBAS executables. This activity is significant as adversaries often use LOLBAS techniques to execute malicious code stealthily, potentially indicating lateral movement or code execution attempts.
    If confirmed malicious, this behavior could allow attackers to execute arbitrary commands, escalate privileges, or maintain persistence within the environment, posing a significant security risk.
data_source:
    - Sysmon EventID 1
    - CrowdStrike ProcessRollup2
search: |-
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime

    FROM datamodel=Endpoint.Processes WHERE

    Processes.parent_process = "*"
    Processes.parent_process_name = "svchost.exe"
    Processes.process_name IN (
        "At.exe", "Atbroker.exe", "Bash.exe", "Bitsadmin.exe", "Certoc.exe", "Cmstp.exe",
        "Diskshadow.exe", "Dnscmd.exe", "Extexport.exe", "Forfiles.exe", "Ftp.exe",
        "Gpscript.exe", "Hh.exe", "Ie4uinit.exe", "Ieexec.exe", "Infdefaultinstall.exe",
        "Installutil.exe", "Mavinject.exe", "Microsoft.Workflow.Compiler.exe",
        "Msbuild.exe", "Msconfig.exe", "Msdt.exe", "Msiexec.exe", "Netsh.exe",
        "Odbcconf.exe", "OfflineScannerShell.exe", "Pcalua.exe", "Pcwrun.exe",
        "Pnputil.exe", "PresentationHost.exe", "Rasautou.exe", "Regasm.exe",
        "Register-cimprovider.exe", "Regsvcs.exe", "Regsvr32.exe", "Runonce.exe",
        "Runscripthelper.exe", "Schtasks.exe", "Scriptrunner.exe", "SettingSyncHost.exe",
        "Stordiag.exe", "Syncappvpublishingserver.exe", "Ttdinject.exe", "Mshta.exe",
        "Tttracer.exe", "Verclsid.exe", "Wab.exe", "Wmic.exe",
        "WorkFolders.exe", "Wuauclt.exe", "Xwizard.exe"
    )
    NOT (
        Processes.parent_process IN ("*-k GPSvcGroup*", "*-k netsvcs", "*-k netsvcs -p","*-k netsvcs -p -s gpsvc")
        Processes.process_name = "Gpscript.exe"
    )
    NOT (
        Processes.parent_process IN ("*-k netsvcs", "*-k netsvcs -p", "*-k netsvcs -p -s wuauserv", "-k netsvcs -p -s Schedule")
        Processes.process_name IN ("Wuauclt.exe", "Schtasks.exe")
    )
    NOT (
        Processes.parent_process = "*-k DcomLaunch*"
        Processes.process_name IN ("PresentationHost.exe", "SettingSyncHost.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)`
    | `svchost_lolbas_execution_process_spawn_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: Legitimate applications may trigger this behavior, filter as needed.
references:
    - https://attack.mitre.org/techniques/T1053/005/
    - https://www.ired.team/offensive-security/persistence/t1053-schtask
    - https://lolbas-project.github.io/
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 ("$dest$") | 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: The parent process[$parent_process$] spawned a Living Off The Land process [$process_name$] on [$dest$]
    entity:
        field: dest
        type: system
        score: 50
threat_objects:
    - field: parent_process
      type: process
    - field: process_name
      type: process_name
analytic_story:
    - Active Directory Lateral Movement
    - Living Off The Land
    - Scheduled Tasks
    - Hellcat Ransomware
asset_type: Endpoint
mitre_attack_id:
    - T1053.005
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1053.005/svchost_lolbas_execution_process_spawn/windows-xml.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      test_type: unit