Windows User Discovery Via Net

Name:Windows User Discovery Via Net
id:7742987e-88c1-476b-a626-a869e088ab72
version:7
date:None
author:Mauricio Velazco, Teoderick Contreras, Nasreddine Bencherchali, Splunk
status:production
type:Hunting
Description:The following analytic detects the execution of `net.exe` or `net1.exe` with command-line arguments `user` or `users` to query local and domain accounts. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as it indicates potential reconnaissance efforts by adversaries to enumerate local and domain users, which is a common step in situational awareness and Active Directory discovery. If confirmed malicious, this behavior could lead to further attacks, including privilege escalation and lateral movement within the network.
Data_source:

• -Sysmon EventID 1
• -Windows Event Log Security 4688
• -CrowdStrike ProcessRollup2

search:| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime

FROM datamodel=Endpoint.Processes WHERE

`process_net`

Processes.process IN (
"*user *",
"*user",
"*users *",
"*users"
)
NOT Processes.process IN (
"*/add*",
"*/active*",
"*/delete*",
"*/times*"
)

BY Processes.action Processes.dest Processes.original_file_name
Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
Processes.process Processes.process_exec Processes.process_guid
Processes.process_hash Processes.process_id Processes.process_integrity_level
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)`
| `windows_user_discovery_via_net_filter`

how_to_implement:The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives:Administrators or power users may use this command for troubleshooting.
References:
  -https://attack.mitre.org/techniques/T1087/001/
  -https://attack.mitre.org/techniques/T1087/002/
  -https://ss64.com/nt/net-user.html
  -https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/net-user?source=recommendations#parameters
drilldown_searches:
  :
analytic_story:['Active Directory Discovery', 'Sandworm Tools', 'Medusa Ransomware']

asset_type:Endpoint

mitre_attack_id:['T1087.001', 'T1087.002']

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

category:endpoint

security_domain:endpoint

tags:

tests:
 name:'True Positive Test - Local User Discovery'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1087.001/AD_discovery/windows-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
 test_type:'unit'
 name:'True Positive Test - Domain User Discovery'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1087.002/AD_discovery/windows-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
 test_type:'unit'
manual_test:None