Detection: MacOS LoginHook Persistence

Description

Identifies attempts to configure a macOS LoginHook via the defaults utility. LoginHooks enable automatic execution of a script or program upon user login and have historically been abused for persistence. Creation or modification of this setting may indicate an attempt to establish startup execution outside standard LaunchAgent mechanisms.

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime
 4        max(_time) as lastTime
 5
 6from datamodel=Endpoint.Processes where
 7
 8Processes.process = "*defaults *"
 9Processes.process = "*write*"
10Processes.process = "*loginwindow*"
11Processes.process = "*loginhook*"
12
13by Processes.dest Processes.original_file_name Processes.parent_process_id
14   Processes.process Processes.process_exec Processes.process_guid
15   Processes.process_hash Processes.process_id
16   Processes.process_current_directory Processes.process_name
17   Processes.process_path Processes.user
18   Processes.user_id Processes.vendor_product
19
20
21| `drop_dm_object_name(Processes)`
22
23| `security_content_ctime(firstTime)`
24
25| `security_content_ctime(lastTime)`
26
27| `macos_loginhook_persistence_filter`

Data Source

Name Platform Sourcetype Source
Osquery Results Other 'osquery:results' 'osquery'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
macos_loginhook_persistence_filter search *
macos_loginhook_persistence_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1037.002 Login Hook Persistence
Exploitation
Installation
DE.CM
CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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 must be deployed across your indexers and universal forwarders in order to have the osquery data populate the data models.

Known False Positives

This method is possibly still used by legacy enterprise management scripts. Update filter macro to remove false positives.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Loginhook created on $dest$ by $user$ via $process$

Risk Object Risk Object Type Risk Score Threat Objects
dest system 50 process
user user 50 process

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Passing N/A N/A N/A
Unit Passing Dataset osquery osquery:results
Integration ✅ Passing Dataset osquery osquery:results

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: GitHub | Version: 2