Detection rules › Splunk

MacOS Account Created

Status
production
Severity
low
Group by
CurrentDirectory, command_line, computer_name, original_file_name, parent_process_id, process_guid, process_hash, process_id, process_name, user, user_id, vendor_product
Author
Raven Tait, Splunk
Source
github.com/splunk/security_content

The following analytic detects the creation of a new local user account on a MacOS system. It leverages osquery logs to identify this activity. Monitoring the creation of local accounts is crucial for a SOC as it can indicate unauthorized access or lateral movement within the network. If confirmed malicious, this activity could allow an attacker to establish persistence, escalate privileges, or gain unauthorized access to sensitive systems and data.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1136 Create Account

Rule body splunk

name: MacOS Account Created
id: 491004ae-694f-453e-b1e0-fc1e65daeea1
version: 3
creation_date: '2026-04-14'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: Anomaly
description: |-
    The following analytic detects the creation of a new local user account on a MacOS system. It leverages osquery logs to identify this activity.
    Monitoring the creation of local accounts is crucial for a SOC as it can indicate unauthorized access or lateral movement within the network.
    If confirmed malicious, this activity could allow an attacker to establish persistence, escalate privileges, or gain unauthorized access to sensitive systems and data.
data_source:
    - Osquery Results
search: |-
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime
    from datamodel=Endpoint.Processes where
    
    (
        Processes.process = "*sysadminctl"
        Processes.process = "*-addUser*"
    )
    OR
    (
        Processes.process = "*createhomedir*"
        Processes.process = "*-u*"
    )
    OR
    (
        Processes.process = "*dseditgroup*"
        Processes.process IN (
            "*edit*",
            "*-a*"
            )
    )
    OR
    (
        Processes.process = "*dscl*"
        Processes.process = "*-create*"
    )
    
    by Processes.dest Processes.original_file_name Processes.parent_process_id
       Processes.process Processes.process_exec Processes.process_guid
       Processes.process_hash Processes.process_id
       Processes.process_current_directory Processes.process_name
       Processes.process_path Processes.user Processes.user_id
       Processes.vendor_product
    
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `macos_account_created_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.
    Also the [TA-OSquery](https://splunkbase.splunk.com/app/8574) must be deployed across your indexers and universal forwarders in order to have the osquery data populate the data models.
known_false_positives: |-
    Creating new accounts after initial endpoint management should be rare in most environments. Investigate and tune as needed.
references:
    - https://osquery.readthedocs.io/en/stable/deployment/process-auditing/
    - https://ss64.com/mac/sysadminctl.html
    - https://ss64.com/mac/dseditgroup.html
    - https://ss64.com/mac/dscl.html
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: New local account created on $dest$ by $user$ via $process$
        - field: dest
          type: system
          score: 20
          message: New local account created on $dest$ by $user$ via $process$
threat_objects:
    - field: process
      type: process
analytic_story:
    - MacOS Persistence Techniques
asset_type: Endpoint
mitre_attack_id:
    - T1136
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1136/osquery_account_creation/osquery.log
          source: osquery
          sourcetype: osquery:results
      test_type: unit

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime
from datamodel=Endpoint.Processes where

(
    Processes.process = "*sysadminctl"
    Processes.process = "*-addUser*"
)
OR
(
    Processes.process = "*createhomedir*"
    Processes.process = "*-u*"
)
OR
(
    Processes.process = "*dseditgroup*"
    Processes.process IN (
        "*edit*",
        "*-a*"
        )
)
OR
(
    Processes.process = "*dscl*"
    Processes.process = "*-create*"
)

by Processes.dest Processes.original_file_name Processes.parent_process_id
   Processes.process Processes.process_exec Processes.process_guid
   Processes.process_hash Processes.process_id
   Processes.process_current_directory Processes.process_name
   Processes.process_path Processes.user Processes.user_id
   Processes.vendor_product

Stage 2: search

| `drop_dm_object_name(Processes)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `macos_account_created_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Processes.processeq
  • "*-addUser*"
  • "*-create*"
  • "*-u*"
  • "*createhomedir*"
  • "*dscl*"
  • "*dseditgroup*"
  • "*sysadminctl"
Processes.processin
  • "*-a*"
  • "*edit*"