Require that application add-ins are signed by Trusted Publisher

UserNeeds changes for IntuneL_RequirethatApplicationExtensionsaresigned

Supported on SUPPORTED_Windows7 (defined in the Windows templates)

5568.1000

What it does

This policy setting controls whether add-ins for this applications must be digitally signed by a trusted publisher. If you enable this policy setting, this application checks the digital signature for each add-in before loading it. If an add-in does not have a digital signature, or if the signature did not come from a trusted publisher, this application disables the add-in and notifies the user. Certificates must be added to the Trusted Publishers list if you require that all add-ins be signed by a trusted publisher. For detail on about obtaining and distributing certificates, see http://go.microsoft.com/fwlink/?LinkId=294922. Office 2016 stores certificates for trusted publishers in the Internet Explorer trusted publisher store. Earlier versions of Microsoft Office stored trusted publisher certificate information (specifically, the certificate thumbprint) in a special Office trusted publisher store. Office 2016 still reads trusted publisher certificate information from the Office trusted publisher store, but it does not write information to this store. Therefore, if you created a list of trusted publishers in a previous version of Office and you upgrade to Office 2016, your trusted publisher list will still be recognized. However, any trusted publisher certificates that you add to the list will be stored in the Internet Explorer trusted publisher store. For more information about trusted publishers, see the Office Resource Kit. If you disable or do not configure this policy setting, this application does not check the digital signature on application add-ins before opening them. If a dangerous add-in is loaded, it could harm users' computers or compromise data security.

What it writes

Hive: HKEY_CURRENT_USER
Registry key: software\policies\microsoft\office\16.0\access\security
Value name: requireaddinsig
When enabled: DWORD 1
When disabled: DWORD 0

Why it needs changes for Intune

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

Configure and deploy

Choose a state; 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\16.0\access\security]
"requireaddinsig"=dword:00000001

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: Require that application add-ins are signed by Trusted Publisher
# Name: L_RequirethatApplicationExtensionsaresigned
# Scope: User
# State: Enabled
# Source: access16.admx

Set-RegistryValue -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\access\security' -Name 'requireaddinsig' -PropertyType 'DWord' -Value 1

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.

ADMX profile candidate (OMA-URI)

./User/Vendor/MSFT/Policy/Config/ADMX_access16/L_RequirethatApplicationExtensionsaresigned

ADMX SyncML candidate

<SyncML xmlns="SYNCML:SYNCML1.2">
  <SyncBody>
    <Replace>
      <CmdID>1</CmdID>
      <Item>
        <Meta>
          <Format>chr</Format>
          <Type>text/plain</Type>
        </Meta>
        <Target>
          <LocURI>./User/Vendor/MSFT/Policy/Config/ADMX_access16/L_RequirethatApplicationExtensionsaresigned</LocURI>
        </Target>
        <Data>&lt;enabled/&gt;</Data>
      </Item>
    </Replace>
    <Final/>
  </SyncBody>
</SyncML>

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: Require that application add-ins are signed by Trusted Publisher
# Name: L_RequirethatApplicationExtensionsaresigned
# Scope: User
# State: Enabled
# Source: access16.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\access\security' -Name 'requireaddinsig' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\access\security\requireaddinsig') | 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: Require that application add-ins are signed by Trusted Publisher
# Name: L_RequirethatApplicationExtensionsaresigned
# Scope: User
# State: Enabled
# Source: access16.admx

Set-RegistryValue -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\access\security' -Name 'requireaddinsig' -PropertyType 'DWord' -Value 1

History 1 retained release

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

Template

Internal name: L_RequirethatApplicationExtensionsaresigned
Namespace: access16.Office.Microsoft.Policies.Windows
Template file: access16.admx
Release: Microsoft 365 Apps 5568.1000 · file set 8be05d876aae137d…

Definition, editor controls and support

Definition

<policy class="User" displayName="$(string.L_RequirethatApplicationExtensionsaresigned)" explainText="$(string.L_RequirethatApplicationExtensionsaresignedExplain)" key="software\policies\microsoft\office\16.0\access\security" name="L_RequirethatApplicationExtensionsaresigned" valueName="requireaddinsig" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="access16.Office.Microsoft.Policies.Windows:L_TrustCenter" />
      <supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
      <enabledValue>
        <decimal value="1" />
      </enabledValue>
      <disabledValue>
        <decimal value="0" />
      </disabledValue>
    </policy>

Editor controls

Supported platforms and category

access16.Office.Microsoft.Policies.Windows:category:L_ApplicationSettings
<category displayName="$(string.L_ApplicationSettings)" name="L_ApplicationSettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="access16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeaccess" />
    </category>
access16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeaccess
<category displayName="$(string.L_MicrosoftOfficeaccess)" name="L_MicrosoftOfficeaccess" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
access16.Office.Microsoft.Policies.Windows:category:L_Security
<category displayName="$(string.L_Security)" name="L_Security" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="access16.Office.Microsoft.Policies.Windows:L_ApplicationSettings" />
    </category>
access16.Office.Microsoft.Policies.Windows:category:L_TrustCenter
<category displayName="$(string.L_TrustCenter)" name="L_TrustCenter" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="access16.Office.Microsoft.Policies.Windows:L_Security" />
    </category>
access16.Office.Microsoft.Policies.Windows:unresolved:Microsoft.Policies.Windows:SUPPORTED_Windows7
<unresolved reference="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
access16.Office.Microsoft.Policies.Windows:category:L_ApplicationSettings
<category displayName="$(string.L_ApplicationSettings)" name="L_ApplicationSettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="access16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeaccess" />
    </category>
<strings><string id="access16.Office.Microsoft.Policies.Windows:L_ApplicationSettings">Application Settings</string></strings>
access16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeaccess
<category displayName="$(string.L_MicrosoftOfficeaccess)" name="L_MicrosoftOfficeaccess" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="access16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeaccess">Microsoft Access 2016</string></strings>
access16.Office.Microsoft.Policies.Windows:category:L_Security
<category displayName="$(string.L_Security)" name="L_Security" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="access16.Office.Microsoft.Policies.Windows:L_ApplicationSettings" />
    </category>
<strings><string id="access16.Office.Microsoft.Policies.Windows:L_Security">Security</string></strings>
access16.Office.Microsoft.Policies.Windows:category:L_TrustCenter
<category displayName="$(string.L_TrustCenter)" name="L_TrustCenter" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="access16.Office.Microsoft.Policies.Windows:L_Security" />
    </category>
<strings><string id="access16.Office.Microsoft.Policies.Windows:L_TrustCenter">Trust Center</string></strings>