Windows Default Rdp File Unhidden

name: Windows Default Rdp File Unhidden
id: f5c1f64b-db59-4913-991e-3dac8adff288
version: 4
date: '2026-03-10'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: This detection identifies the use of attrib.exe to remove hidden (-h) or system (-s) attributes from the Default.rdp file, which is automatically created in a user's Documents folder when a Remote Desktop Protocol (RDP) session is initiated using mstsc.exe. The Default.rdp file stores session configuration details such as the remote host address and screen settings. Unhiding this file is uncommon in normal user behavior and may indicate that an attacker or red team operator is attempting to access or manipulate RDP connection history that was previously hidden—either by default or as part of an earlier anti-forensics effort. This activity may represent part of a broader pattern of reconnaissance or staging for credential reuse, lateral movement, or forensic analysis evasion. Monitoring for this behavior can help uncover suspicious manipulation of user artifacts and highlight interactive attacker activity on a compromised host.
data_source:
    - Sysmon EventID 1
search: |-
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
      WHERE Processes.process_name = "attrib.exe" Processes.process IN("*-s*", "*-h*") Processes.process = "*default.rdp*"
      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_default_rdp_file_unhidden_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: No false positives have been identified at this time.
references:
    - https://medium.com/@bonguides25/how-to-clear-rdp-connections-history-in-windows-cf0ffb67f344
    - https://thelocalh0st.github.io/posts/rdp/
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") starthoursago=168  | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: A process unhiding default.rdp on $dest$.
    risk_objects:
        - field: dest
          type: system
          score: 20
    threat_objects:
        - field: parent_process_name
          type: parent_process_name
tags:
    analytic_story:
        - Windows RDP Artifacts and Defense Evasion
    asset_type: Endpoint
    mitre_attack_id:
        - T1021.001
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1021.001/unhide_file/unhide_file.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog