Block additional file extensions for OLE embedding

UserNeeds changes for IntuneL_BlockedExtensions

Supported on SUPPORTED_Windows7 (defined in the Windows templates)

5568.1000

What it does

This policy setting only applies to subscription versions of Office, such as Microsoft 365 Apps for enterprise, and to subscription versions of Project and Visio. This policy setting allows you to specify additional file extensions that Office will block when they are embedded as an OLE package in an Office file by using the Object Packager control. By default, Office blocks certain file extensions. For a list of those file extensions, go to https://go.microsoft.com/fwlink/?linkid=847759. Important: Malicious scripts and executables can be embedded as an OLE package and can cause harm if clicked by the user. If you enable this policy setting, enter the additional file extensions to block, separated by semicolons. For example, py;rb. If you disable or don’t configure this policy setting, the default set of file extensions will be blocked. If you want to allow certain file extensions, enable the "Allow file extensions for OLE embedding" policy setting. Extensions added to this policy setting will take precedence over extensions in "Allow file extensions for OLE embedding"

What it writes

Hive: HKEY_CURRENT_USER
Registry key: software\policies\microsoft\office\common\security

Why it needs changes for Intune

Policy references a Windows supportedOn definition.
ADMX-INTUNE-WINDOWS-SUPPORTEDON-REFERENCE

Options

Option	Type	Registry value	Allowed values
File extensions	Text	`blockedextensions`	Up to 255 characters

Configure and deploy

Choose a state and the option values; the output below is generated from the template for exactly that.

Enabled · User · template defaults

Registry file (.reg)

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\software\policies\microsoft\office\common\security]
"blockedextensions"=""

PowerShell

$ErrorActionPreference = 'Stop'

function Set-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $PropertyType,
        [Parameter(Mandatory = $true)][object] $Value
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        New-Item -Path $Path -Force | Out-Null
    }

    New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}

function Remove-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (Test-Path -LiteralPath $Path) {
        Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
    }
}

function Clear-RegistryKeyValues {
    param(
        [Parameter(Mandatory = $true)][string] $Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return
    }

    foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
        Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
    }
}

# Policy: Block additional file extensions for OLE embedding
# Name: L_BlockedExtensions
# Scope: User
# State: Enabled
# Source: office16.admx

Set-RegistryValue -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\common\security' -Name 'blockedextensions' -PropertyType 'String' -Value ''

The OMA-URI is an inferred ADMX-backed Policy CSP candidate derived from the source ADMX file name and policy name.
Some Microsoft policies use built-in Policy CSP pages whose area names don't match the ADMX file name, so verify the candidate against Microsoft Learn before deployment.
The generated payload is incomplete because one or more ADMX element values were not supplied: L_blockedextensionsole

ADMX profile candidate (OMA-URI)

./User/Vendor/MSFT/Policy/Config/ADMX_office16/L_BlockedExtensions

Intune remediation scripts

Detection

$ErrorActionPreference = 'Stop'
$reasons = [System.Collections.Generic.List[string]]::new()

function Test-RegistryValueExists {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return $false
    }

    return $null -ne (Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue)
}

function Test-RegistryValueEquals {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $Kind,
        [Parameter(Mandatory = $true)][object] $Expected
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return $false
    }

    $valueObject = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue
    if ($null -eq $valueObject) {
        return $false
    }

    $actual = $valueObject.$Name
    switch ($Kind) {
        'String' { return [string]$actual -ceq [string]$Expected }
        'ExpandString' { return [string]$actual -ceq [string]$Expected }
        'DWord' { return [uint32]$actual -eq [uint32]$Expected }
        'QWord' { return [uint64]$actual -eq [uint64]$Expected }
        'MultiString' {
            $actualArray = @($actual)
            $expectedArray = @($Expected)
            if ($actualArray.Count -ne $expectedArray.Count) { return $false }
            for ($index = 0; $index -lt $actualArray.Count; $index++) {
                if ([string]$actualArray[$index] -cne [string]$expectedArray[$index]) { return $false }
            }
            return $true
        }
        'Binary' {
            $actualArray = [byte[]]$actual
            $expectedArray = [byte[]]$Expected
            if ($actualArray.Length -ne $expectedArray.Length) { return $false }
            for ($index = 0; $index -lt $actualArray.Length; $index++) {
                if ($actualArray[$index] -ne $expectedArray[$index]) { return $false }
            }
            return $true
        }
        default { return [string]$actual -ceq [string]$Expected }
    }
}

# Policy: Block additional file extensions for OLE embedding
# Name: L_BlockedExtensions
# Scope: User
# State: Enabled
# Source: office16.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\common\security' -Name 'blockedextensions' -Kind 'String' -Expected ''
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_CURRENT_USER\software\policies\microsoft\office\common\security\blockedextensions') | Out-Null
}

if ($reasons.Count -eq 0) {
    Write-Output 'Compliant'
    exit 0
}

$reasons | ForEach-Object { Write-Output $_ }
exit 1

Remediation

$ErrorActionPreference = 'Stop'

function Set-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $PropertyType,
        [Parameter(Mandatory = $true)][object] $Value
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        New-Item -Path $Path -Force | Out-Null
    }

    New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}

function Remove-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (Test-Path -LiteralPath $Path) {
        Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
    }
}

function Clear-RegistryKeyValues {
    param(
        [Parameter(Mandatory = $true)][string] $Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return
    }

    foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
        Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
    }
}

# Policy: Block additional file extensions for OLE embedding
# Name: L_BlockedExtensions
# Scope: User
# State: Enabled
# Source: office16.admx

Set-RegistryValue -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\common\security' -Name 'blockedextensions' -PropertyType 'String' -Value ''

History 1 retained release

5568.100010 Aug 2026
- Already present in the first release ChangeIntel keeps.

Template

Internal name: L_BlockedExtensions
Namespace: office16.Office.Microsoft.Policies.Windows
Template file: office16.admx
Release: Microsoft 365 Apps 5568.1000 · file set 8be05d876aae137d…

Definition, editor controls and support

Definition

<policy class="User" displayName="$(string.L_BlockedExtensions)" explainText="$(string.L_BlockedExtensionsExplain)" key="software\policies\microsoft\office\common\security" name="L_BlockedExtensions" presentation="$(presentation.L_BlockedExtensions)" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="office16.Office.Microsoft.Policies.Windows:L_SecuritySettings" />
      <supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
      <elements>
        <text id="L_blockedextensionsole" valueName="blockedextensions" />
      </elements>
    </policy>

Editor controls

<presentation id="L_BlockedExtensions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <textBox refId="L_blockedextensionsole">
          <label>File extensions:</label>
        </textBox>
      </presentation>

Supported platforms and category

office16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeSystem
<category displayName="$(string.L_MicrosoftOfficeSystem)" name="L_MicrosoftOfficeSystem" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
office16.Office.Microsoft.Policies.Windows:category:L_SecuritySettings
<category displayName="$(string.L_SecuritySettings)" name="L_SecuritySettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="office16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeSystem" />
    </category>
office16.Office.Microsoft.Policies.Windows:unresolved:Microsoft.Policies.Windows:SUPPORTED_Windows7
<unresolved reference="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
office16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeSystem
<category displayName="$(string.L_MicrosoftOfficeSystem)" name="L_MicrosoftOfficeSystem" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="office16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeSystem">Microsoft Office 2016</string></strings>
office16.Office.Microsoft.Policies.Windows:category:L_SecuritySettings
<category displayName="$(string.L_SecuritySettings)" name="L_SecuritySettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="office16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeSystem" />
    </category>
<strings><string id="office16.Office.Microsoft.Policies.Windows:L_SecuritySettings">Security Settings</string></strings>