Detection: Windows Remote Service Rdpwinst Tool Execution

Description

The following analytic detects the execution of the RDPWInst.exe tool, which is an RDP wrapper library used to enable remote desktop host support and concurrent RDP sessions. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, original file names, and specific command-line arguments. This activity is significant because adversaries can abuse this tool to establish unauthorized RDP connections, facilitating remote access and potential lateral movement within the network. If confirmed malicious, this could lead to unauthorized access, data exfiltration, and further compromise of the targeted host.

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="RDPWInst.exe" OR Processes.original_file_name="RDPWInst.exe") AND Processes.process IN ("* -i*", "* -s*", "* -o*", "* -w*", "* -r*") by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id 
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `windows_remote_service_rdpwinst_tool_execution_filter`

Data Source

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

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_remote_service_rdpwinst_tool_execution_filter search *
windows_remote_service_rdpwinst_tool_execution_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1021.001 Remote Desktop Protocol Lateral Movement
T1021 Remote Services Lateral Movement
KillChainPhase.EXPLOITAITON
NistCategory.DE_CM
Cis18Value.CIS_10
APT1
APT3
APT39
APT41
APT5
Agrius
Aquatic Panda
Axiom
Blue Mockingbird
Chimera
Cobalt Group
Dragonfly
FIN10
FIN13
FIN6
FIN7
FIN8
Fox Kitten
HEXANE
INC Ransom
Indrik Spider
Kimsuky
Lazarus Group
Leviathan
Magic Hound
OilRig
Patchwork
Silence
Volt Typhoon
Wizard Spider
menuPass
Aquatic Panda
Ember Bear
Wizard Spider

Default Configuration

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

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

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

This tool was designed for home usage and not commonly seen in production environment. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Rdpwinst.exe executed on $dest$. 81 90 90
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Passing N/A N/A N/A
Unit Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog

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: 4