Windows: Malicious Child Process Execution via vsjitdebugger.exe Just-In-Time Debugger

title: "Windows: Malicious Child Process Execution via vsjitdebugger.exe Just-In-Time Debugger"
id: 28bf9b48-73aa-4b25-ad2c-d2310795eb49
status: test
description: This rule identifies process creation where the parent process is Microsoft Visual Studio Just-In-Time Debugger (vsjitdebugger.exe), but excludes likely benign helper/debugger scenarios. Attackers can abuse this functionality to launch and run arbitrary executables under the context of a trusted, developer-installed component. It relies on process creation telemetry capturing both the parent image path and the spawned child image path on Windows.
references:
  - https://twitter.com/pabraeken/status/990758590020452353
  - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Vsjitdebugger/
  - https://learn.microsoft.com/en-us/visualstudio/debugger/debug-using-the-just-in-time-debugger?view=vs-2019
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_susp_use_of_vsjitdebugger_bin.yml
author: Agro (@agro_sev), Ensar Şamil (@sblmsrsn), oscd.community, Huntrule Team
date: 2020-10-14
modified: 2022-10-09
tags:
  - attack.stealth
  - attack.t1218
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: \vsjitdebugger.exe
  reduction1:
    Image|endswith: \vsimmersiveactivatehelper*.exe
  reduction2:
    Image|endswith: \devenv.exe
  condition: selection and not (reduction1 or reduction2)
falsepositives:
  - The process spawned by vsjitdebugger.exe is uncommon.
level: medium
license: DRL-1.1
related:
  - id: 15c7904e-6ad1-4a45-9b46-5fb25df37fd2
    type: derived