Detection: MacOS Network Share Discovery

Updated Date: 2026-04-15 ID: a5f5fe52-8e50-4fb0-ad1b-780be6c0d857 Author: Raven Tait, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

Identifies execution of network share enumeration commands (smbutil, showmount) that can be leveraged by adversaries to discover accessible SMB and NFS resources, supporting internal reconnaissance and potential lateral movement.

Search

 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 IN ("*showmount *", "*smbutil *")
 9
10by Processes.dest Processes.original_file_name Processes.parent_process_id
11   Processes.process Processes.process_exec Processes.process_guid
12   Processes.process_hash Processes.process_id
13   Processes.process_current_directory Processes.process_name
14   Processes.process_path Processes.user
15   Processes.user_id Processes.vendor_product
16
17
18| `drop_dm_object_name(Processes)`
19
20| `security_content_ctime(firstTime)`
21
22| `security_content_ctime(lastTime)`
23
24| `macos_network_share_discovery_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_network_share_discovery_filter	`search *`

macos_network_share_discovery_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
T1135	Network Share Discovery	Discovery

Exploitation

DE.AE

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 Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

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

Administrators may utilize these tools occasionaly for troubleshooting.

Associated Analytic Story

MacOS Post-Exploitation

Risk Based Analytics (RBA)

Risk Message:

Network share information enumerated on $dest$ by $user$ via $process$

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	20	process
user	user	20	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