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Description

This analytic identifies potential adversaries that modify the security permission of a specific file or directory. This technique is commonly seen in APT tradecraft and coinminer scripts to evade detections and restrict access to their component files.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-05-04
  • Author: Teoderick Contreras, Splunk
  • ID: b1b1e316-accc-11eb-a9b4-acde48001122

ATT&CK

ID Technique Tactic
T1222 File and Directory Permissions Modification Defense Evasion

| tstats `security_content_summariesonly` values(Processes.process) as process values(Processes.process_id) as process_id count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name = "icacls.exe" OR Processes.process_name = "cacls.exe" OR Processes.process_name = "xcacls.exe" AND Processes.process = "*/grant*" by Processes.parent_process_name Processes.process_name Processes.dest Processes.user 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `icacls_grant_command_filter`

Associated Analytic Story

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 icacls.exe may be used.

Required field

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

Kill Chain Phase

  • Exploitation

Known False Positives

Unknown. Filter as needed.

RBA

Risk Score Impact Confidence Message
49.0 70 70 Process name $process_name$ with grant argument executed by $user$ to change security permission of a specific file or directory on host $dest$

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

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