Modification of IE Registry Settings

Severity: low
Author: frack113
Source: upstream

Detects modification of the registry settings used for Internet Explorer and other Windows components that use these settings. An attacker can abuse this registry key to add a domain to the trusted sites Zone or insert JavaScript for persistence

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_domains`

TargetObject|contains: '\Software\Microsoft\Windows\CurrentVersion\Internet Settings'

Stage 2: `not 1 of filter_main_*`

or:
Details: '(Empty)'
Details: 'Binary Data'
Details: 'Cookie:'
Details: 'Visited:'
Details: null
Details|startswith: DWORD
TargetObject|contains: '\Cache'
TargetObject|contains: '\WpadDecision'
TargetObject|contains: '\ZoneMap'

Stage 3: `not 1 of filter_optional_accepted_documents`

TargetObject|contains: '\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Accepted Documents'

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.

Field	Kind	Values
`Details`	eq	`(Empty)` corpus 24 (sigma 24) `Binary Data` corpus 4 (sigma 4) `Cookie:` `Visited:`
`Details`	starts_with	`DWORD`
`TargetObject`	match	`\Cache` `\Software\Microsoft\Windows\CurrentVersion\Internet Settings` `\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Accepted Documents` `\WpadDecision` `\ZoneMap`