Windows Findstr GPP Discovery
Description
The following analytic detects the use of the findstr command to search for unsecured credentials in Group Policy Preferences (GPP). It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving findstr.exe with references to SYSVOL and cpassword. This activity is significant because it indicates an attempt to locate and potentially decrypt embedded credentials in GPP, which could lead to unauthorized access. If confirmed malicious, this could allow an attacker to escalate privileges or gain access to sensitive systems and data within the domain.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2024-05-29
- Author: Mauricio Velazco, Splunk
- ID: 1631ac2d-f2a9-42fa-8a59-d6e210d472f5
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name=findstr.exe AND Processes.process=*sysvol* AND Processes.process=*cpassword*) by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.original_file_name
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_findstr_gpp_discovery_filter`
Macros
The SPL above uses the following Macros:
windows_findstr_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
- Processes.user
- Processes.dest
- Processes.process_name
- Processes.process
- Processes.dest
- Processes.user
- Processes.parent_process_name
- Processes.process_name
- Processes.process_id
- Processes.parent_process_id
- Processes.original_file_name
How To Implement
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes
node of the Endpoint
data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known False Positives
Administrators may leverage findstr to find passwords in GPO to validate exposure. Filter as needed.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
56.0 | 70 | 80 | Findstr was executed to discover GPP credentials 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
- 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://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