Windows Proxy Via Netsh

name: Windows Proxy Via Netsh
id: c137bfe8-6036-4cff-b77b-4e327dd0a1cf
version: 9
date: '2026-03-10'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
description: The following analytic identifies the use of netsh.exe to configure a connection proxy, which can be leveraged for persistence by executing a helper DLL. It detects this activity by analyzing process creation events from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving "portproxy" and "v4tov4" parameters. This activity is significant because it indicates potential unauthorized network configuration changes, which could be used to maintain persistence or redirect network traffic. If confirmed malicious, this could allow an attacker to maintain covert access or manipulate network communications, posing a significant security risk.
search: |-
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
      WHERE `process_netsh` Processes.process = "* portproxy *" Processes.process = "* v4tov4 *"
      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_proxy_via_netsh_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: Some VPN applications are known to launch netsh.exe. Outside of these instances, it is unusual for an executable to launch netsh.exe and run commands.
references:
    - https://www.microsoft.com/en-us/security/blog/2023/05/24/volt-typhoon-targets-us-critical-infrastructure-with-living-off-the-land-techniques/
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user$"
      search: '%original_detection_search% | search  dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") 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: A process $process_name$ has launched netsh with command-line $process$ on $dest$.
    risk_objects:
        - field: dest
          type: system
          score: 20
        - field: user
          type: user
          score: 20
    threat_objects: []
tags:
    analytic_story:
        - Volt Typhoon
    asset_type: Endpoint
    atomic_guid:
        - b8223ea9-4be2-44a6-b50a-9657a3d4e72a
    mitre_attack_id:
        - T1090.001
    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/T1090.001/netsh_portproxy/volt_sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog