ClickOnce Trust Prompt Tampering — Sigma Rule

Rule metadata and linked tags

Author: @SerkinValery, Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2023-06-12 / 2023-08-17.

{
  "category": "registry_set",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 20692f544c276c00ee15a566516312945c167bda966a143734df07c56d7498e8

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: ClickOnce Trust Prompt Tampering
id: ac9159cc-c364-4304-8f0a-d63fc1a0aabb
status: test
description: Detects changes to the ClickOnce trust prompt registry key in order to enable an installation from different locations such as the Internet.
references:
    - https://posts.specterops.io/less-smartscreen-more-caffeine-ab-using-clickonce-for-trusted-code-execution-1446ea8051c5
    - https://learn.microsoft.com/en-us/visualstudio/deployment/how-to-configure-the-clickonce-trust-prompt-behavior
author: '@SerkinValery, Nasreddine Bencherchali (Nextron Systems)'
date: 2023-06-12
modified: 2023-08-17
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel\'
        TargetObject|endswith:
            - '\Internet'
            - '\LocalIntranet'
            - '\MyComputer'
            - '\TrustedSites'
            - '\UntrustedSites'
        Details: 'Enabled'
    condition: selection
falsepositives:
    - Legitimate internal requirements.
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate internal requirements.

Source references

• https://posts.specterops.io/less-smartscreen-more-caffeine-ab-using-clickonce-for-trusted-code-execution-1446ea8051c5
• https://learn.microsoft.com/en-us/visualstudio/deployment/how-to-configure-the-clickonce-trust-prompt-behavior