Detection: Windows Process Execution From RDP Share

Description

The following analytic identifies process executions originating from RDP shares on Windows endpoints. Remote Desktop Protocol (RDP) shares, typically accessed via the "tsclient" path, allow users to share files between their local machine and a remote desktop session. However, threat actors may exploit RDP shares to execute malicious processes or transfer harmful files onto a compromised system. This detection focuses on identifying any process executions that originate from RDP shares, which could indicate unauthorized access or malicious activity. Security teams should investigate any instances of such process executions, especially if they are found on systems that should not be using RDP shares or if the executed processes are unfamiliar or suspicious.

Search

 1
 2| tstats `security_content_summariesonly`
 3
 4  count min(_time) as firstTime 
 5        max(_time) as lastTime 
 6
 7from datamodel=Endpoint.Processes where
 8
 9Processes.process = "*\\\\tsclient\\*"
10
11by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
12Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
13Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
14Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
15Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
16
17
18| `drop_dm_object_name(Processes)`
19
20| `security_content_ctime(firstTime)`
21
22| `security_content_ctime(lastTime)`
23
24| `windows_process_execution_from_rdp_share_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

Legitimate use of RDP shares by users to transfer and execute files may trigger this detection. It is essential to review the context of the process execution to determine if it is authorized activity.

Associated Analytic Story

• Hidden Cobra Malware

Risk Based Analytics (RBA)

Risk Message:

Process $process_name$ executed $process$ from RDP share on host $dest$

References

• https://jsac.jpcert.or.jp/archive/2024/pdf/JSAC2024_2_7_hara_shoji_higashi_vickie-su_nick-dai_en.pdf

• https://thedfirreport.com/2020/04/04/gogoogle-ransomware/

• https://www.welivesecurity.com/2022/09/30/amazon-themed-campaigns-lazarus-netherlands-belgium/

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: 1