Detection rules › Splunk

Windows PowerSploit GPP Discovery

Status
production
Severity
medium
Group by
Guid, Name, Opcode, Path, ScriptBlockId, ScriptBlockText, dest, process_id, signature, signature_id, user_id, vendor_product
Author
Mauricio Velazco, Splunk
Source
github.com/splunk/security_content

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.

MITRE ATT&CK coverage

Event coverage

Rule body splunk

name: Windows PowerSploit GPP Discovery
id: 0130a0df-83a1-4647-9011-841e950ff302
version: 15
creation_date: '2023-03-16'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: TTP
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.
data_source:
    - Powershell Script Block Logging 4104
search: |-
    `powershell` EventCode=4104  (ScriptBlockText=Get-GPPPassword OR ScriptBlockText=Get-CachedGPPPassword)
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY dest signature signature_id
           user_id vendor_product EventID
           Guid Opcode Name
           Path ProcessID ScriptBlockId
           ScriptBlockText
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_powersploit_gpp_discovery_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://help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba.
known_false_positives: No false positives have been identified at this time.
references:
    - 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
drilldown_searches:
    - name: View the detection results for - "$Computer$" and "$user$"
      search: '%original_detection_search% | search  Computer = "$Computer$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$Computer$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$Computer$", "$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: Commandlets leveraged to discover GPP credentials were executed on $dest$
    entity:
        field: user_id
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: Commandlets leveraged to discover GPP credentials were executed on $dest$
analytic_story:
    - Active Directory Privilege Escalation
asset_type: Endpoint
mitre_attack_id:
    - T1552.006
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1552.006/powershell_gpp_discovery/win-powershell.log
          source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: search

`powershell` EventCode=4104  (ScriptBlockText=Get-GPPPassword OR ScriptBlockText=Get-CachedGPPPassword)

Stage 2: fillnull

| fillnull

Stage 3: stats

| stats count min(_time) as firstTime max(_time) as lastTime
    BY dest signature signature_id
       user_id vendor_product EventID
       Guid Opcode Name
       Path ProcessID ScriptBlockId
       ScriptBlockText

Stage 4: search

| `security_content_ctime(firstTime)`

Stage 5: search

| `security_content_ctime(lastTime)`

Stage 6: search

| `windows_powersploit_gpp_discovery_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
EventCodeeq
  • 4104 corpus 268 (splunk 268)
ScriptBlockTexteq
  • Get-CachedGPPPassword
  • Get-GPPPassword