huntrule

Windows RDP Session Hijacking via tscon.exe from System Integrity

Flags tscon.exe executions on Windows running at System integrity, indicating potential RDP session hijacking.

FreeUnreviewedSigmamediumv1
title: Windows RDP Session Hijacking via tscon.exe from System Integrity
id: b1a2081d-f2fc-45b9-bc0f-5053df29f668
status: test
description: This rule identifies suspicious use of tscon.exe associated with RDP session redirection or hijacking. It focuses on process creation events where tscon.exe executes with a high integrity level (System), which attackers may abuse to take control of sessions or move them between contexts. Telemetry relies on Windows process creation logs, including the image path or OriginalFileName and the process integrity level.
references:
  - https://twitter.com/Moti_B/status/909449115477659651
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_tscon_rdp_session_hijacking.yml
author: "@juju4, Huntrule Team"
date: 2022-12-27
modified: 2024-12-01
tags:
  - attack.execution
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith: \tscon.exe
    - OriginalFileName: tscon.exe
  selection_integrity:
    IntegrityLevel:
      - System
      - S-1-16-16384
  condition: all of selection_*
falsepositives:
  - Administrative activity
level: medium
license: DRL-1.1
related:
  - id: 224f140f-3553-4cd1-af78-13d81bf9f7cc
    type: derived

What it detects

This rule identifies suspicious use of tscon.exe associated with RDP session redirection or hijacking. It focuses on process creation events where tscon.exe executes with a high integrity level (System), which attackers may abuse to take control of sessions or move them between contexts. Telemetry relies on Windows process creation logs, including the image path or OriginalFileName and the process integrity level.

Known false positives

  • Administrative activity

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.