Windows ClickOnce Deployment Execution via dfsvc.exe Child Process

Flags ClickOnce-style child processes spawned by dfsvc.exe from the AppData\Local\Apps\2.0\ directory on Windows.

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windows-clickonce-deployment-execution-via-dfsvc-exe-child-process-241d52b5

title: Windows ClickOnce Deployment Execution via dfsvc.exe Child Process
id: b1f887be-7e25-4388-90a9-c674344519c1
status: test
description: This rule identifies process creation events where the parent executable is dfsvc.exe and the child process image path ends in the ClickOnce applications directory (AppData\Local\Apps\2.0\). This matters because ClickOnce deployment execution can be abused to run application content through a trusted Windows mechanism. The detection relies on Windows process creation telemetry, specifically the parent/child image paths reported by event logging.
references:
  - https://posts.specterops.io/less-smartscreen-more-caffeine-ab-using-clickonce-for-trusted-code-execution-1446ea8051c5
  - https://github.com/SigmaHQ/sigma/blob/master/rules-threat-hunting/windows/process_creation/proc_creation_win_dfsvc_child_processes.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2023-06-12
tags:
  - attack.execution
  - detection.threat-hunting
  - attack.stealth
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: \dfsvc.exe
    Image|endswith: \AppData\Local\Apps\2.0\
  condition: selection
falsepositives:
  - False positives are expected in environement leveraging ClickOnce deployments. An initial baselining is required before using this rule in production.
level: medium
license: DRL-1.1
related:
  - id: 241d52b5-eee0-49d0-ac8a-8b9c15c7221c
    type: derived

What it detects

This rule identifies process creation events where the parent executable is dfsvc.exe and the child process image path ends in the ClickOnce applications directory (AppData\Local\Apps\2.0\). This matters because ClickOnce deployment execution can be abused to run application content through a trusted Windows mechanism. The detection relies on Windows process creation telemetry, specifically the parent/child image paths reported by event logging.

Known false positives

False positives are expected in environement leveraging ClickOnce deployments. An initial baselining is required before using this rule in production.

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