XSL Script Execution With WMIC

Try in Splunk Security Cloud

Description

This search is to detect a suspicious wmic.exe process or renamed wmic process to execute malicious xsl file. This technique was seen in FIN7 to execute its malicous jscript using the .xsl as the loader with the help of wmic.exe process. This TTP is really a good indicator for you to hunt further for FIN7 or other attacker that known to used this technique.

• Type: TTP
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-09-13
• 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

CIS20

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:

• security_content_summariesonly
• security_content_ctime
• process_wmic

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.

Supported Add-on (TA)

List of Splunk Add-on’s tested to work with the analytic.

• Splunk Add-on for Sysmon

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

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

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

• https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/fin7/fin7_macro_js_1/sysmon.log

source | version: 1