Detection: Detect Remote Access Software Usage Registry

Description

The following analytic detects when a known remote access software is added to common persistence locations on a device within the environment. Adversaries use these utilities to retain remote access capabilities to the environment. Utilities in the lookup include AnyDesk, GoToMyPC, LogMeIn, TeamViewer and much more. Review the lookup for the entire list and add any others.

Search

 1
 2| tstats `security_content_summariesonly` latest(Registry.process_guid) as process_guid  count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry where (Registry.registry_path="*\\Microsoft\\Windows\\CurrentVersion\\Run*" OR (Registry.registry_path="*\\SYSTEM\\CurrentControlSet\\Services\\*" AND Registry.registry_value_name="ImagePath")) by Registry.dest Registry.user Registry.registry_path Registry.registry_value_name Registry.registry_value_data Registry.registry_key_name 
 3| `drop_dm_object_name(Registry)` 
 4| `security_content_ctime(firstTime)` 
 5| `security_content_ctime(lastTime)` 
 6| rex field=registry_value_data "(\")?.+\\\(?<file_name_1>[^\"=]+\.[^\" ]{1,5})(\")?" 
 7| rex field=registry_value_data "(?<file_name_2>[^\.]+\.[^\" ]{1,5}$)" 
 8| eval file_name = coalesce(file_name_1,file_name_2) 
 9| lookup remote_access_software remote_utility AS file_name OUTPUT isutility, description as signature, comment_reference as desc, category 
10| search isutility = TRUE 
11| `remote_access_software_usage_exceptions` 
12| `detect_remote_access_software_usage_registry_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 12	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Sysmon EventID 13	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

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 file path, file name, and the user that created the file. 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 Registry 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. The "exceptions" macro leverages both an Assets and Identities lookup, as well as a KVStore collection called "remote_software_exceptions" that lets you track and maintain device-based exceptions for this set of detections.

Known False Positives

Known or approved applications used by the organization or usage of built-in functions. Known false positives can be added to the remote_access_software_usage_exception.csv lookup to globally suppress these situations across all remote access content

Associated Analytic Story

• CISA AA24-241A

• Command And Control

• Gozi Malware

• Insider Threat

• Ransomware

Risk Based Analytics (RBA)

Risk Message:

A process for a known remote access software [$signature$] was detected on $dest$

References

• https://attack.mitre.org/techniques/T1219/

• https://thedfirreport.com/2022/08/08/bumblebee-roasts-its-way-to-domain-admin/

• https://thedfirreport.com/2022/11/28/emotet-strikes-again-lnk-file-leads-to-domain-wide-ransomware/

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: 2