XSL Script Execution With WMIC

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Description

The following analytic detects the execution of an XSL script using the WMIC process, which is often indicative of malicious activity. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving WMIC and XSL files. This behavior is significant as it has been associated with the FIN7 group, known for using this technique to execute malicious scripts. If confirmed malicious, this activity could allow attackers to execute arbitrary code, potentially leading to system compromise and further malicious actions within the environment.

• Type: TTP
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2024-05-13
• Author: Teoderick Contreras, Splunk
• ID: 004e32e2-146d-11ec-a83f-acde48001122

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1220	XSL Script Processing	Defense Evasion

Kill Chain Phase

• Exploitation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_wmic` Processes.process = "*os get*" Processes.process="*/format:*" Processes.process = "*.xsl*" by Processes.parent_process_name Processes.parent_process Processes.process_name Processes.process_id Processes.process Processes.dest Processes.user 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `xsl_script_execution_with_wmic_filter`

Macros

The SPL above uses the following Macros:

• process_wmic
• security_content_ctime
• security_content_summariesonly

xsl_script_execution_with_wmic_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.parent_process_name
• Processes.parent_process
• Processes.process_name
• Processes.process_id
• Processes.process
• Processes.dest
• Processes.user

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

unknown

Associated Analytic Story

• FIN7
• Suspicious WMI Use

RBA

Risk Score	Impact	Confidence	Message
49.0	70	70	An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ utilizing wmic to load a XSL script.

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

• https://www.mandiant.com/resources/fin7-pursuing-an-enigmatic-and-evasive-global-criminal-operation
• https://attack.mitre.org/groups/G0046/
• https://web.archive.org/web/20190814201250/https://subt0x11.blogspot.com/2018/04/wmicexe-whitelisting-bypass-hacking.html
• https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1220/T1220.md#atomic-test-3—wmic-bypass-using-local-xsl-file

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

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