Windows Default Rdp File Unhidden

Name:Windows Default Rdp File Unhidden
id:f5c1f64b-db59-4913-991e-3dac8adff288
version:1
date:2025-07-30
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:unknown
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:'$info_max_time$'
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
manual_test:None