ClickOnce Trust Prompt Tampering

Severity: medium
Author: @SerkinValery, Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects changes to the ClickOnce trust prompt registry key in order to enable an installation from different locations such as the Internet.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1112` Modify Registry
Defense Evasion	`T1112` Modify Registry

Event coverage

Provider	Event ID	Title
Sysmon	13	RegistryEvent (Value Set)

Stages and Predicates

Stage 1: `selection`

or:
TargetObject|endswith: '\Internet'
TargetObject|endswith: '\LocalIntranet'
TargetObject|endswith: '\MyComputer'
TargetObject|endswith: '\TrustedSites'
TargetObject|endswith: '\UntrustedSites'
Details: Enabled
TargetObject|contains: '\SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel\'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.