Outlook EnableUnsafeClientMailRules Setting Enabled - Registry

Severity: high
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects an attacker trying to enable the outlook security setting "EnableUnsafeClientMailRules" which allows outlook to run applications or execute macros

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`

Details: 'DWORD (0x00000001)'
TargetObject|endswith: '\Outlook\Security\EnableUnsafeClientMailRules'

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.