Ensure 'Prevent Excel from running XLM macros' is set to 'Enabled'

AltaNivel 1Automatizadaoffice

Descripción

This policy setting will prevent Excel from running Excel 4.0 (XLM) macros. XLM macros were first added to Excel in 1992 and were disabled in Excel (Build 16.0.14427.10000) by Microsoft in 2021. The recommended state for this setting is: Enabled. Rationale: XLM is data macro format from the early nineties that was not built with security in mind. Macros can be easily exploited and are a favorite hiding place of malicious code. User setting: the audit checks HKEY_USERS\<SID>\SOFTWARE\Policies\Microsoft\office\16.0\excel\security:xl4macrooff (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.

Cómo se verifica

Método de auditoría: Registro de 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\' + $s + '\SOFTWARE\Policies\Microsoft\office\16.0\excel\security') -Name 'xl4macrooff' -ErrorAction SilentlyContinue).'xl4macrooff'; if (-not ($null -ne $v -and @(1) -contains [int64]$v)) { $bad += $s + ':xl4macrooff=' + $v } }; if ($bad.Count -eq 0) { 'compliant' } else { 'non-compliant: ' + ($bad -join ', ') } }

Salida esperada: compliant

Cómo se corrige

Método de corrección: Guía o parche de infraestructura

Configure through Group Policy (User Configuration): User Configuration\Administrative Templates\Microsoft Excel 2016\Excel Options\Security\Trust Center\Prevent Excel from running XLM macros = Enabled

Propiedades

Sistemas operativos: Cualquiera
Etiquetas: officeproductivitycis-l1
Referencia: CIS Microsoft Office Enterprise Benchmark v2.0.0 - 2.2.4.7.2.10 Ensure 'Prevent Excel from running XLM macros' is set to 'Enabled'

Verificar este host

Ejecute esto en un equipo que tenga permiso para auditar. El escaneo es de solo lectura.

shell

tmaegis scan --target office