Name:Windows Account Discovery for None Disable User Account id:eddbf5ba-b89e-47ca-995e-2d259804e55e version:4 date:2024-10-17 author:Teoderick Contreras, Splunk status:production type:Hunting Description:The following analytic detects the execution of the PowerView PowerShell cmdlet Get-NetUser with the UACFilter parameter set to NOT_ACCOUNTDISABLE, indicating an attempt to enumerate Active Directory user accounts that are not disabled. This detection leverages PowerShell Script Block Logging (EventCode 4104) to identify the specific script block text. Monitoring this activity is significant as it may indicate reconnaissance efforts by an attacker to identify active user accounts for further exploitation. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, or lateral movement within the network. Data_source:
-Powershell Script Block Logging 4104
search:`powershell` EventCode=4104 ScriptBlockText = "*Get-NetUser*" ScriptBlockText = "*NOT_ACCOUNTDISABLE*" ScriptBlockText = "*-UACFilter*" | rename Computer as dest, UserID as user | stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText dest user | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_account_discovery_for_none_disable_user_account_filter`
how_to_implement:To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.= known_false_positives:Administrators may leverage PowerView for legitimate purposes, filter as needed. References: -https://www.cisa.gov/news-events/cybersecurity-advisories/aa23-347a -https://powersploit.readthedocs.io/en/stable/Recon/README/ -https://book.hacktricks.xyz/windows-hardening/basic-powershell-for-pentesters/powerview -https://atomicredteam.io/discovery/T1087.001/ drilldown_searches:
: tags: analytic_story: - 'CISA AA23-347A' asset_type:Endpoint confidence:50 impact:30 message:Windows Account Discovery for None Disable User Account using PowerView's Get-NetUser on $dest$. mitre_attack_id: - 'T1087' - 'T1087.001' observable: name:'dest' type:'Hostname' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' risk_score:15 required_fields: - '_time' - 'ScriptBlockText' - 'dest' - 'EventCode' - 'user' security_domain:endpoint
