Detection rules › Splunk

Windows Remote Service Rdpwinst Tool Execution

Status
production
Severity
medium
Group by
IntegrityLevel, command_line, computer_name, event_action, original_file_name, parent_command_line, parent_process_guid, parent_process_id, parent_process_name, process_guid, process_hash, process_id, process_name, user, user_id, vendor_product
Author
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

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.

Known false positives

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

MITRE ATT&CK coverage

Telemetry coverage

Rule body

name: Windows Remote Service Rdpwinst Tool Execution
id: c8127f87-c7c9-4036-89ed-8fe4b30e678c
version: 14
creation_date: '2022-07-06'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
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.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |-
    | 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.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
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_remote_service_rdpwinst_tool_execution_filter`
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: This tool was designed for home usage and not commonly seen in production environment. Filter as needed.
references:
    - https://app.any.run/tasks/a6f2ffe2-e6e2-4396-ae2e-04ea0143f2d8/
finding:
    title: Rdpwinst.exe executed on $dest$.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Azorult
    - Compromised Windows Host
    - Windows RDP Artifacts and Defense Evasion
    - Scattered Lapsus$ Hunters
asset_type: Endpoint
mitre_attack_id:
    - T1021.001
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: tstats

| 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.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

Stage 2: search

| `drop_dm_object_name(Processes)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_remote_service_rdpwinst_tool_execution_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Processes.original_file_nameeq
  • "RDPWInst.exe"
field:"OriginalFileName" kind:eq
Processes.processin
  • "* -i*"
  • "* -o*" corpus 8 (sigma 6, elastic 1, chronicle 1)
  • "* -r*" corpus 4 (sigma 3, splunk 1)
  • "* -s*" corpus 3 (sigma 3)
  • "* -w*"
field:"CommandLine" kind:in
Processes.process_nameeq
  • "RDPWInst.exe"
field:"process_name" kind:eq