huntrule

Windows: conhost.exe spawned by uncommon parent process

Alerts on conhost.exe launched by an uncommon parent process, using process creation parent image and command-line context.

FreeReviewedSigma · Medium · v2
Product
windows
Category
process_creation
Author
Tim Rauch, Elastic (idea) (SigmaHQ), DRL 1.1
Published
2022-09-28
Updated
2026-07-31
AnalysisDetection
title: "Windows: conhost.exe spawned by uncommon parent process"
id: 95608482-93ab-4310-ae65-93a0271e5253
status: test
description: This rule flags process creation events where conhost.exe is started by a parent process that is not commonly expected, excluding specific service-hosting command lines and a known Dropbox path. Attackers may leverage unexpected process trees to execute or inject code while using console host behavior to blend in. It relies on Windows process creation telemetry, matching conhost.exe by filename and evaluating the parent process image and parent command line.
references:
  - https://www.elastic.co/guide/en/security/current/conhost-spawned-by-suspicious-parent-process.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_conhost_uncommon_parent.yml
author: Tim Rauch, Elastic (idea), Huntrule Team
date: 2022-09-28
modified: 2025-03-06
tags:
  - attack.execution
  - attack.t1059
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith: \conhost.exe
    ParentImage|endswith:
      - \explorer.exe
      - \lsass.exe
      - \regsvr32.exe
      - \rundll32.exe
      - \services.exe
      - \smss.exe
      - \spoolsv.exe
      - \svchost.exe
      - \userinit.exe
      - \wininit.exe
      - \winlogon.exe
  filter_main_svchost:
    ParentCommandLine|contains:
      - -k apphost -s AppHostSvc
      - -k imgsvc
      - -k localService -p -s RemoteRegistry
      - -k LocalSystemNetworkRestricted -p -s NgcSvc
      - -k NetSvcs -p -s NcaSvc
      - -k netsvcs -p -s NetSetupSvc
      - -k netsvcs -p -s wlidsvc
      - -k NetworkService -p -s DoSvc
      - -k wsappx -p -s AppXSvc
      - -k wsappx -p -s ClipSVC
      - -k wusvcs -p -s WaaSMedicSvc
  filter_optional_dropbox:
    ParentCommandLine|contains:
      - C:\Program Files (x86)\Dropbox\Client\
      - C:\Program Files\Dropbox\Client\
  condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: cbb9e3d1-2386-4e59-912e-62f1484f7a89
    type: derived