GPUpdate with no Command Line Arguments with Network

name: GPUpdate with no Command Line Arguments with Network
id: 2c853856-a140-11eb-a5b5-acde48001122
version: 14
date: '2026-03-10'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects the execution of gpupdate.exe without command line arguments and with an active network connection. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process execution and network traffic data. It is significant because gpupdate.exe typically runs with specific arguments, and its execution without them, especially with network activity, is often associated with malicious software like Cobalt Strike. If confirmed malicious, this activity could indicate an attacker leveraging gpupdate.exe for lateral movement, command and control, or other nefarious purposes, potentially leading to system compromise.
data_source:
    - Sysmon EventID 1 AND Sysmon EventID 3
search: |-
    | tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes
      WHERE Processes.process_name=gpupdate.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)`
    | regex process="(?i)(gpupdate\.exe.{0,4}$)"
    | join  process_id [
    | tstats `security_content_summariesonly` count values(All_Traffic.app) as app values(All_Traffic.dest_ip) as dest_ip values(All_Traffic.direction) as direction values(All_Traffic.dvc) as dvc values(All_Traffic.protocol) as protocol values(All_Traffic.protocol_version) as protocol_version values(All_Traffic.src) as src values(All_Traffic.src_ip) as src_ip values(All_Traffic.src_port) as src_port values(All_Traffic.transport) as transport FROM datamodel=Network_Traffic.All_Traffic
      WHERE All_Traffic.dest_port != 0
      BY All_Traffic.process_id All_Traffic.dest All_Traffic.dest_port
    | `drop_dm_object_name(All_Traffic)`
    | rename dest as C2 ]
    | table _time user dest parent_process_name process_name process_path process process_id dest_port C2 app dest_ip direction dvc protocol protocol_version src src_ip src_port transport
    | `gpupdate_with_no_command_line_arguments_with_network_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 may be present in small environments. Tuning may be required based on parent process.
references:
    - https://raw.githubusercontent.com/xx0hcd/Malleable-C2-Profiles/0ef8cf4556e26f6d4190c56ba697c2159faa5822/crimeware/trick_ryuk.profile
    - https://www.cobaltstrike.com/blog/learn-pipe-fitting-for-all-of-your-offense-projects/
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 ("$user$", "$dest$") 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: Process gpupdate.exe with parent_process $parent_process_name$ is executed on $dest$ by user $user$, followed by an outbound network connection on port $dest_port$. This behaviour is seen with cobaltstrike.
    risk_objects:
        - field: user
          type: user
          score: 50
        - field: dest
          type: system
          score: 50
    threat_objects:
        - field: parent_process_name
          type: parent_process_name
tags:
    analytic_story:
        - Graceful Wipe Out Attack
        - Cobalt Strike
        - Compromised Windows Host
        - BlackByte Ransomware
        - Hellcat Ransomware
    asset_type: Endpoint
    mitre_attack_id:
        - T1055
    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/T1055/cobalt_strike/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog