Windows PowerSploit GPP Discovery

Try in Splunk Security Cloud

Description

The following analytic detects the execution of the Get-GPPPassword PowerShell cmdlet, which is used to search for unsecured credentials in Group Policy Preferences (GPP). This detection leverages PowerShell Script Block Logging to identify specific script block text associated with this cmdlet. Monitoring this activity is crucial as it can indicate an attempt to retrieve and decrypt stored credentials from SYSVOL, potentially leading to unauthorized access. If confirmed malicious, this activity could allow an attacker to escalate privileges or move laterally within the network by exploiting exposed credentials.

• Type: TTP

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2024-05-12
• Author: Mauricio Velazco, Splunk
• ID: 0130a0df-83a1-4647-9011-841e950ff302

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1552	Unsecured Credentials	Credential Access

T1552.006

Group Policy Preferences

Credential Access

Kill Chain Phase

• Exploitation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

 `powershell` EventCode=4104  (ScriptBlockText=Get-GPPPassword OR ScriptBlockText=Get-CachedGPPPassword) 
| stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer UserID EventCode ScriptBlockText 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_powersploit_gpp_discovery_filter`

Macros

The SPL above uses the following Macros:

• powershell
• security_content_ctime

windows_powersploit_gpp_discovery_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
• EventCode
• ScriptBlockText
• Opcode
• Computer
• UserID

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

Unknown

Associated Analytic Story

• Active Directory Privilege Escalation

RBA

Risk Score	Impact	Confidence	Message
56.0	70	80	Commandlets leveraged to discover GPP credentials were executed on $Computer$

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

• https://attack.mitre.org/techniques/T1552/006/
• https://pentestlab.blog/2017/03/20/group-policy-preferences/
• https://adsecurity.org/?p=2288
• https://www.hackingarticles.in/credential-dumping-group-policy-preferences-gpp/
• https://adsecurity.org/?p=2288
• https://support.microsoft.com/en-us/topic/ms14-025-vulnerability-in-group-policy-preferences-could-allow-elevation-of-privilege-may-13-2014-60734e15-af79-26ca-ea53-8cd617073c30

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