splunk-security_content/docs/_posts/2021-07-27-chcp_command_execution.md

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title	excerpt	categories	last_modified_at	toc	toc_label	tags
CHCP Command Execution	Command and Scripting Interpreter	Endpoint	2021-07-27	true		Command and Scripting Interpreter Execution Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint

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Description

This search is to detect execution of chcp.exe application. this utility is used to change the active code page of the console. This technique was seen in icedid malware to know the locale region/language/country of the compromise host.

• Type: TTP
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-07-27
• Author: Teoderick Contreras, Splunk
• ID: 21d236ec-eec1-11eb-b23e-acde48001122

Annotations

ATT&CK

ID	Technique	Tactic
T1059	Command and Scripting Interpreter	Execution

Kill Chain Phase

• Reconnaissance

NIST

CIS20

CVE

Search

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=chcp.com Processes.parent_process_name = cmd.exe Processes.parent_process=*/c* by  Processes.process_name Processes.process Processes.parent_process_name Processes.parent_process Processes.process_id Processes.parent_process_id Processes.dest Processes.user 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `chcp_command_execution_filter`

Macros

The SPL above uses the following Macros:

• security_content_ctime
• security_content_summariesonly

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

Required field

• _time
• process_name
• process
• parent_process_name
• parent_process
• process_id
• parent_process_id
• dest
• 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. Tune and filter known instances where renamed chcp.com may be used.

Known False Positives

other tools or script may used this to change code page to UTF-* or others

Associated Analytic story

• IcedID
• Azorult

RBA

Risk Score	Impact	Confidence	Message
9.0	30	30	parent process parent_process_name spawning chcp process process_name with parent command line parent_process

ℹ️ 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://ss64.com/nt/chcp.html
• https://twitter.com/tccontre18/status/1419941156633329665?s=20

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/icedid/simulated_icedid/windows-sysmon.log

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