Try in Splunk Security Cloud

Description

The following analytic detects the usage of the plutil command to modify plist files on macOS systems. It leverages osquery to monitor process events, specifically looking for executions of /usr/bin/plutil. This activity is significant because adversaries can use plutil to alter plist files, potentially adding malicious binaries or command-line arguments that execute upon user logon or system startup. If confirmed malicious, this could allow attackers to achieve persistence, execute arbitrary code, or escalate privileges, posing a significant threat to the system's security.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-22
  • Author: Patrick Bareiss, Splunk
  • ID: c11f2b57-92c1-4cd2-b46c-064eafb833ac

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1647 Plist File Modification Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6
7



`osquery_macro` name=es_process_events columns.path=/usr/bin/plutil 
| rename columns.* as * 
| stats count  min(_time) as firstTime max(_time) as lastTime by username host cmdline pid path parent signing_id 
| rename username as user, cmdline as process, path as process_path, host as dest 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
| `macos_plutil_filter`

Macros

The SPL above uses the following Macros:

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

Required fields

List of fields required to use this analytic.

  • _time
  • columns.cmdline
  • columns.pid
  • columns.parent
  • columns.path
  • columns.signing_id
  • columns.username
  • host

How To Implement

This detection uses osquery and endpoint security on MacOS. Follow the link in references, which describes how to setup process auditing in MacOS with endpoint security and osquery.

Known False Positives

Administrators using plutil to change plist files.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
25.0 50 50 plutil are executed on $dest$ from $user$

:information_source: 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

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

source | version: 4