Suspicious Child Process of KeyScrambler.exe on Windows

Alerts on KeyScrambler.exe launching cmd.exe, PowerShell, script hosts, regsvr32, or rundll32 as child processes.

FreeReviewedSigma · Medium · v2
Product
windows
Category
process_creation
Author
Swachchhanda Shrawan Poudel (SigmaHQ), DRL 1.1
Published
2024-05-13
Updated
2026-07-31
title: Suspicious Child Process of KeyScrambler.exe on Windows
id: 6883cd75-ec0b-442d-8aa7-81fa9074d661
related:
  - id: d2451be2-b582-4e15-8701-4196ac180260
    type: similar
  - id: ca5583e9-8f80-46ac-ab91-7f314d13b984
    type: derived
status: test
description: This rule flags process creation events where the parent process ends with \KeyScrambler.exe and the child process matches common script, command, and execution utilities. Such child processes may indicate attempts to extend KeyScrambler.exe behavior for persistence, execution, privilege escalation, or stealth. It relies on Windows process creation telemetry that includes ParentImage, Image, and OriginalFileName for accurate matching.
references:
  - https://twitter.com/DTCERT/status/1712785421845790799
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_keyscrambler_susp_child_process.yml
author: Swachchhanda Shrawan Poudel, Huntrule Team
date: 2024-05-13
tags:
  - attack.persistence
  - attack.execution
  - attack.privilege-escalation
  - attack.stealth
  - attack.t1203
  - attack.t1574.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_parent:
    ParentImage|endswith: \KeyScrambler.exe
  selection_binaries:
    - Image|endswith:
        - \cmd.exe
        - \cscript.exe
        - \mshta.exe
        - \powershell.exe
        - \pwsh.exe
        - \regsvr32.exe
        - \rundll32.exe
        - \wscript.exe
    - OriginalFileName:
        - Cmd.Exe
        - cscript.exe
        - mshta.exe
        - PowerShell.EXE
        - pwsh.dll
        - regsvr32.exe
        - RUNDLL32.EXE
        - wscript.exe
  condition: all of selection_*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1