Detection: GPUpdate with no Command Line Arguments with Network

Updated Date: 2025-05-02 ID: 2c853856-a140-11eb-a5b5-acde48001122 Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

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.

 1
 2| 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 
 3| `drop_dm_object_name(Processes)` 
 4| `security_content_ctime(firstTime)` 
 5| `security_content_ctime(lastTime)` 
 6| regex process="(?i)(gpupdate\.exe.{0,4}$)"
 7| join  process_id [
 8| 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 
 9| `drop_dm_object_name(All_Traffic)` 
10| rename dest as C2 ] 
11| 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 
12| `gpupdate_with_no_command_line_arguments_with_network_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 1 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Sysmon EventID 3 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
gpupdate_with_no_command_line_arguments_with_network_filter search *
gpupdate_with_no_command_line_arguments_with_network_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1055 Process Injection Defense Evasion
Exploitation
DE.CM
CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk 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 Object Risk Object Type Risk Score Threat Objects
user user 81 parent_process_name
dest system 81 parent_process_name

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 11

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