Ensure 'Block Excel XLL Add-ins that come from an untrusted source' is set to 'Enabled: Blocked'

ÉlevéeNiveau 1Automatiséeoffice

Description

An Excel add-in is a collection of custom code and functionality that enhances Microsoft Excel's capabilities. These add-ins can be created by third-party developers or by Excel users themselves. Once installed, they become part of Excel and can be used across different workbooks. .XLL Add-ins are native code add-ins written in C or C++ programming languages. Rationale: Untrusted XLL files, as dynamic-link libraries (DLLs), pose a security risk in phishing campaigns, where attackers can trick users into executing seemingly harmless files containing malicious payloads. User setting: the audit checks HKEY_USERS\<SID>\SOFTWARE\Policies\Microsoft\office\16.0\excel\security:blockxllfrominternet (REG_DWORD) in every loaded user hive (S-1-5-21-*) and is compliant when each holds 1. It prints 'no-user-hive-loaded' (FAIL) when no user profile is loaded, so scan while users are logged on.

Méthode de vérification

Méthode d'audit: Registre Windows

registry

$sids = @(Get-ChildItem -Path 'Registry::HKEY_USERS' -ErrorAction SilentlyContinue | Where-Object { $_.PSChildName -match '^S-1-5-21-\d+-\d+-\d+-\d+$' } | ForEach-Object { $_.PSChildName }); if ($sids.Count -eq 0) { 'no-user-hive-loaded' } else { $bad = @(); foreach ($s in $sids) { $v = (Get-ItemProperty -Path ('Registry::HKEY_USERS\' + $s + '\SOFTWARE\Policies\Microsoft\office\16.0\excel\security') -Name 'blockxllfrominternet' -ErrorAction SilentlyContinue).'blockxllfrominternet'; if (-not ($null -ne $v -and @(1) -contains [int64]$v)) { $bad += $s + ':blockxllfrominternet=' + $v } }; if ($bad.Count -eq 0) { 'compliant' } else { 'non-compliant: ' + ($bad -join ', ') } }

Sortie attendue: compliant

Méthode de correction

Méthode de correction: Recommandation ou correctif d'infrastructure

Configure through Group Policy (User Configuration): User Configuration\Administrative Templates\Microsoft Excel 2016\Excel Options\Security\Trust Center\Block Excel XLL Add-ins that come from an untrusted source = Enabled

Propriétés

Systèmes d'exploitation: Tous
Étiquettes: officeproductivitycis-l1
Référence: CIS Microsoft Office Enterprise Benchmark v2.0.0 - 2.2.4.7.2.5 Ensure 'Block Excel XLL Add-ins that come from an untrusted source' is set to 'Enabled: Blocked'

Vérifier cet hôte

Exécutez cette commande sur une machine que vous êtes autorisé à auditer. L'analyse est en lecture seule.

shell

tmaegis scan --target office