Windows Domain Account Discovery Via Get-NetComputer
Description
The following analytic leverages Event ID 4104 to identify the execution of the PowerView powershell commandlets Get-NetComputer. This technique was seen used in the context of PowerView's Get-NetUser cmdlet as a filter or parameter to query Active Directory user account's "samccountname", "accountexpires", "lastlogon" and so on. This hunting query is a good pivot to look for suspicious process or malware that gather user account information in a host or within network system.
- Type: Anomaly
-
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2023-12-15
- Author: Teoderick Contreras, Splunk
- ID: a7fbbc4e-4571-424a-b627-6968e1c939e4
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.AE
CIS20
- CIS 10
CVE
Search
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`powershell` EventCode=4104 ScriptBlockText = "*Get-NetComputer*" ScriptBlockText IN ("*samaccountname*", "*accountexpires*", "*lastlogon*", "*lastlogoff*", "*pwdlastset*", "*logoncount*")
| 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_domain_account_discovery_via_get_netcomputer_filter`
Macros
The SPL above uses the following Macros:
windows_domain_account_discovery_via_get-netcomputer_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
- ScriptBlockText
- dest
- EventCode
- user
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.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
15.0 | 30 | 50 | Windows Domain Account Discovery Via Get-NetComputer in $dest$. |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
Test Dataset
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 | version: 1