Windows InstallUtil URL in Command Line

SPLUNK detection rule by Michael Haag, Splunk · Apache-2.0

The following analytic detects the use of Windows InstallUtil.exe with an HTTP or HTTPS URL in the command line. This is identified through Endpoint Detection and Response (EDR) telemetry, focusing on command-line executions containing URLs. This activity is significant as it may indicate an attempt to download and execute malicious code, potentially bypassing application control mechanisms. If confirmed malicious, this could lead to unauthorized code execution, privilege escalation, or persistent access within the environment. Analysts should review the parent process, network connections, file modifications, and related processes for further investigation.

name: Windows InstallUtil URL in Command Line
id: 28e06670-43df-11ec-a569-acde48001122
version: 15
creation_date: '2021-11-12'
modification_date: '2026-07-14'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects the use of Windows InstallUtil.exe with an HTTP or HTTPS URL in the command line. This is identified through Endpoint Detection and Response (EDR) telemetry, focusing on command-line executions containing URLs. This activity is significant as it may indicate an attempt to download and execute malicious code, potentially bypassing application control mechanisms. If confirmed malicious, this could lead to unauthorized code execution, privilege escalation, or persistent access within the environment. Analysts should review the parent process, network connections, file modifications, and related processes for further investigation.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
    - Cisco Network Visibility Module Flow Data
search: |
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
    as lastTime from datamodel=Endpoint.Processes where
    `process_installutil`
    Processes.process IN ("*http://*","*https://*")
    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_installutil_url_in_command_line_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: Limited false positives should be present as InstallUtil is not typically used to download remote files. Filter as needed based on Developers requirements.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.004/T1218.004.md
    - https://gist.github.com/DanielRTeixeira/0fd06ec8f041f34a32bf5623c6dd479d
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: An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ passing a URL on the command-line.
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ passing a URL on the command-line.
threat_objects:
    - field: parent_process_name
      type: parent_process_name
    - field: process_name
      type: process_name
analytic_story:
    - Living Off The Land
    - Compromised Windows Host
    - Signed Binary Proxy Execution InstallUtil
    - Cisco Network Visibility Module Analytics
asset_type: Endpoint
mitre_attack_id:
    - T1218.004
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test - Sysmon
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218.004/atomic_red_team/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit
    - name: True Positive Test - Cisco NVM
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/cisco_network_visibility_module/cisco_nvm_flowdata/nvm_flowdata.log
          source: not_applicable
          sourcetype: cisco:nvm:flowdata:v2
      test_type: unit

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Executable code, not a declarative rule

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Format & documentation suggestions

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