Windows Account Discovery for Sam Account Name
Description
The following analytic detects the execution of the PowerView PowerShell cmdlet Get-NetUser, specifically querying for "samaccountname" and "pwdlastset" attributes. It leverages Event ID 4104 from PowerShell Script Block Logging to identify this activity. This behavior is significant as it may indicate an attempt to gather user account information from Active Directory, which is a common reconnaissance step in lateral movement or privilege escalation attacks. If confirmed malicious, this activity could allow an attacker to map out user accounts, potentially leading to further exploitation and unauthorized access within the network.
- Type: Anomaly
-
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2024-05-30
- Author: Teoderick Contreras, Splunk
- ID: 69934363-e1dd-4c49-8651-9d7663dd4d2f
Annotations
Kill Chain Phase
- Exploitation
NIST
- DE.AE
CIS20
- CIS 10
CVE
Search
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`powershell` EventCode=4104 ScriptBlockText = "*Get-NetUser*" ScriptBlockText IN ("*samaccountname*", "*pwdlastset*")
| 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_sam_account_name_filter`
Macros
The SPL above uses the following Macros:
windows_account_discovery_for_sam_account_name_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 Account Discovery for Sam Account Name on $dest$. |
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: 2