MacOS Network Share Discovery

 Original Source: [splunk source]
Name:MacOS Network Share Discovery
id:a5f5fe52-8e50-4fb0-ad1b-780be6c0d857
version:3
date:None
author:Raven Tait, Splunk
status:production
type:Anomaly
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.
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 IN ("*showmount *", "*smbutil *")

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_network_share_discovery_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:Administrators may utilize these tools occasionaly for troubleshooting.
References:
  -https://osquery.readthedocs.io/en/stable/deployment/process-auditing/
  -https://leopard-adc.pepas.com/documentation/Darwin/Reference/ManPages/man8/showmount.8.html
  -https://www.unix.com/man_page/osx/1/smbutil/
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'
analytic_story:['MacOS Post-Exploitation']

asset_type:Endpoint

mitre_attack_id:['T1135']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:endpoint

security_domain:endpoint

tags:

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1135/osquery_share_discovery/osquery.log
  source: osquery
  sourcetype: osquery:results
 test_type:'unit'
manual_test:None

Related Analytic Stories


MacOS Post-Exploitation