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Description

The following analytic is designed to detect the potential misuse of Windows Management Instrumentation (WMI) for malicious purposes. WMI can be utilized by adversaries to execute scripts, a method often employed for maintaining stealth while carrying out malicious activities. The process 'scrcons.exe', integral to executing WMI scripts, is primarily monitored by this analytic. The underlying threat lies in the fact that successful execution of a malicious script can lead to numerous negative outcomes, including system compromise, data exfiltration, or the establishment of persistence. It's essential for cybersecurity analysts to remain vigilant towards unexpected or isolated script executions via WMI, as such instances often signal suspicious activities or potential security breaches. Although uncommon, administrators may occasionally use WMI to launch scripts for legitimate purposes. Therefore, discerning malicious activities from benign ones is crucial in this context.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2020-03-16
  • Author: Rico Valdez, Michael Haag, Splunk
  • ID: aa73f80d-d728-4077-b226-81ea0c8be589

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1047 Windows Management Instrumentation Execution
Kill Chain Phase
  • Installation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=scrcons.exe by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `script_execution_via_wmi_filter`

Macros

The SPL above uses the following Macros:

:information_source: script_execution_via_wmi_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Processes.process_name
  • Processes.user
  • Processes.dest

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

Although unlikely, administrators may use wmi to launch scripts for legitimate purposes. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
36.0 60 60 A wmic.exe process $process_name$ that execute script in host $dest$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 4