Microsoft Office Trusted Location Updated

SIGMA detection rule by Nasreddine Bencherchali (Nextron Systems) · NOASSERTION

Detects changes to the registry keys related to "Trusted Location" of Microsoft Office. Attackers might add additional trusted locations to avoid macro security restrictions.

title: Microsoft Office Trusted Location Updated
id: a0bed973-45fa-4625-adb5-6ecdf9be70ac
related:
    - id: f742bde7-9528-42e5-bd82-84f51a8387d2
      type: similar
status: test
description: Detects changes to the registry keys related to "Trusted Location" of Microsoft Office. Attackers might add additional trusted locations to avoid macro security restrictions.
references:
    - https://admx.help/?Category=Office2016&Policy=excel16.Office.Microsoft.Policies.Windows::L_TrustedLoc01
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-06-21
modified: 2023-08-17
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
    - detection.threat-hunting
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: 'Security\Trusted Locations\Location'
        TargetObject|endswith: '\Path'
    filter_main_office_click_to_run:
        Image|contains: ':\Program Files\Common Files\Microsoft Shared\ClickToRun\'
        Image|endswith: '\OfficeClickToRun.exe'
    filter_main_office_apps:
        Image|contains:
            - ':\Program Files\Microsoft Office\'
            - ':\Program Files (x86)\Microsoft Office\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - During office installations or setup, trusted locations are added, which will trigger this rule.
level: medium

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

fc07d71b-d627-4902-8ed6-3862aa7ce143

Propose edits, view related rules, and engage with the community through comments.

Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

[[ reason ]]

What does this mean?

Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

[[ reason ]]

What do these messages mean?

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

Community Discussion