excessive_usage_of_cacls_app.yml

name: Excessive Usage Of Cacls App
id: 0bdf6092-af17-11eb-939a-acde48001122
version: 1
date: '2021-05-07'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
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.
data_source:
- Sysmon EventID 1
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`'
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: Administrators or administrative scripts may use this application.
  Filter as needed.
references:
- https://thedfirreport.com/2020/04/20/sqlserver-or-the-miner-in-the-basement/
tags:
  analytic_story:
  - XMRig
  - Azorult
  - Windows Post-Exploitation
  - Prestige Ransomware
  asset_type: Endpoint
  confidence: 100
  impact: 80
  message: An excessive amount of $process_name$ was executed on $dest$ attempting
    to modify permissions.
  mitre_attack_id:
  - T1222
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: process_name
    type: Process
    role:
    - Child Process
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.process
  - Processes.process_id
  - Processes.process_name
  - Processes.parent_process_name
  - Processes.dest
  - Processes.user
  risk_score: 80
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/xmrig_miner/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog