splunk-security_content/docs/_posts/2021-05-07-excessive_usage_of_cacls_app.md

title, excerpt, categories, last_modified_at, toc, toc_label, tags

title	excerpt	categories	last_modified_at	toc	toc_label	tags
Excessive Usage Of Cacls App	File and Directory Permissions Modification	Endpoint	2021-05-07	true		File and Directory Permissions Modification Defense Evasion Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint

Try in Splunk Security Cloud{: .btn .btn--success}

Description

The following analytic identifies excessive usage of cacls.exe, xcacls.exe or icacls.exe application to change file or folder permission. This behavior is commonly seen where the adversary attempts to impair some users from deleting or accessing its malware components or artifact from the compromised system.

• Type: Anomaly
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-05-07
• Author: Teoderick Contreras, Splunk
• ID: 0bdf6092-af17-11eb-939a-acde48001122

ATT&CK

ID	Technique	Tactic
T1222	File and Directory Permissions Modification	Defense Evasion

Search

| tstats `security_content_summariesonly` values(Processes.process) as process values(Processes.process_id) as process_id  values(Processes.process_name) as process_name count min(_time) as firstTime max(_time) as lastTime  from datamodel=Endpoint.Processes where Processes.process_name = "cacls.exe" OR Processes.process_name = "icacls.exe" OR Processes.process_name = "XCACLS.exe" by Processes.parent_process_name Processes.parent_process Processes.dest Processes.user _time span=1m 
| where count >=10 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `excessive_usage_of_cacls_app_filter`

Associated Analytic Story

• XMRig

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node.

Required field

• _time
• Processes.process
• Processes.process_id
• Processes.process_name
• Processes.parent_process_name
• Processes.dest
• Processes.user

Kill Chain Phase

• Exploitation

Known False Positives

Administrators or administrative scripts may use this application. Filter as needed.

RBA

Risk Score	Impact	Confidence	Message
80.0	80	100	An excessive amount of process_name was executed on dest attempting to modify permissions.

Reference

• https://thedfirreport.com/2020/04/20/sqlserver-or-the-miner-in-the-basement/

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/xmrig_miner/windows-sysmon.log

source | version: 1