Detection rules › Splunk

MacOS plutil

Status
production
Severity
medium
Group by
cmdline, host, parent, path, process_id, signing_id, username
Author
Patrick Bareiss, Splunk
Source
github.com/splunk/security_content

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.

Known false positives

  • Administrators using plutil to change plist files.

MITRE ATT&CK coverage

TacticTechniques
Defense Impairment

Rule body

name: MacOS plutil
id: c11f2b57-92c1-4cd2-b46c-064eafb833ac
version: 11
creation_date: '2022-03-04'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: production
type: TTP
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.
data_source:
    - Osquery Results
search: "`osquery_macro` name=es_process_events columns.path=/usr/bin/plutil\n  | rename columns.* as *\n  | stats count  min(_time) as firstTime max(_time) as lastTime\n    BY username host cmdline\n       pid path parent\n       signing_id\n  | rename username as user, cmdline as process, path as process_path, host as dest\n  | `security_content_ctime(firstTime)`\n  | `security_content_ctime(lastTime)`\n  | `macos_plutil_filter`"
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.
references:
    - https://osquery.readthedocs.io/en/stable/deployment/process-auditing/
finding:
    title: plutil are executed on $dest$ from $user$
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: plutil are executed on $dest$ from $user$
analytic_story:
    - Living Off The Land
asset_type: Endpoint
mitre_attack_id:
    - T1647
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: search

`osquery_macro` name=es_process_events columns.path=/usr/bin/plutil

Stage 2: rename

| rename columns.* as *

Stage 3: stats

| stats count  min(_time) as firstTime max(_time) as lastTime
    BY username host cmdline
       pid path parent
       signing_id

Stage 4: rename

| rename username as user, cmdline as process, path as process_path, host as dest

Stage 5: search

| `security_content_ctime(firstTime)`

Stage 6: search

| `security_content_ctime(lastTime)`

Stage 7: search

| `macos_plutil_filter`

Indicators

These rows show field, operator, and value matches.