Detection: Windows Modify Registry Regedit Silent Reg Import

Description

The following analytic detects the modification of the Windows registry using the regedit.exe application with the silent mode parameter. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant because the silent mode allows registry changes without user confirmation, which can be exploited by adversaries to import malicious registry settings. If confirmed malicious, this could enable attackers to persist in the environment, escalate privileges, or manipulate system configurations, leading to potential system compromise.

Search

1
2| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name="regedit.exe" OR Processes.original_file_name="regedit.exe") AND Processes.process="* /s *" AND Processes.process="*.reg*" by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product 
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `windows_modify_registry_regedit_silent_reg_import_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	N/A	'crowdstrike:events:sensor'	'crowdstrike'
Sysmon EventID 1	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Windows Event Log Security 4688	Windows	'xmlwineventlog'	'XmlWinEventLog:Security'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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 execute this command that may cause some false positive. Filter as needed.

Associated Analytic Story

• Azorult

Risk Based Analytics (RBA)

Risk Message:

The regedit app was executed with silet mode parameter to import .reg file on $dest$.

References

• https://app.any.run/tasks/a6f2ffe2-e6e2-4396-ae2e-04ea0143f2d8/

• https://www.techtarget.com/searchwindowsserver/tip/Command-line-options-for-Regeditexe

Detection Testing

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: GitHub | Version: 6