Ensure 'Set default file block behavior' is set to 'Enabled: Blocked files are not opened'

AltaNivel 1Automatizadaoffice

Descripción

This policy setting determines if users can open, view, or edit Excel files that are by default blocked by Microsoft Office. The recommended state for this setting is: Enabled: Blocked files are not opened. Rationale: By default, users can open a wide range of legacy file formats in Office that were not designed with modern security protections in mind. Several of these formats have been associated with vulnerabilities that attackers have exploited. User setting: the audit checks HKEY_USERS\<SID>\SOFTWARE\Policies\Microsoft\office\16.0\excel\security\fileblock:openinprotectedview (REG_DWORD) in every loaded user hive (S-1-5-21-*) and is compliant when each holds 0. 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\' + $s + '\SOFTWARE\Policies\Microsoft\office\16.0\excel\security\fileblock') -Name 'openinprotectedview' -ErrorAction SilentlyContinue).'openinprotectedview'; if (-not ($null -ne $v -and @(0) -contains [int64]$v)) { $bad += $s + ':openinprotectedview=' + $v } }; if ($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\File Block Settings\Set Default File Block Behavior = Enabled: Blocked files are not opened

Propiedades

Sistemas operativos: Cualquiera
Etiquetas: officeproductivitycis-l1
Referencia: CIS Microsoft Office Enterprise Benchmark v2.0.0 - 2.2.4.7.2.2.13 Ensure 'Set default file block behavior' is set to 'Enabled: Blocked files are not opened'

Verificar este host

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

shell

tmaegis scan --target office