System › Filesystem
Enable / disable CLFS logfile authentication
Supported on At least Windows Server 2016, Windows 10 Version 1607
What it does
This policy setting configures CLFS logfile authentication, a security feature which aims to harden logfile parsing. Logfile authentication provides the ability for the CLFS driver to detect malicious modications made to logfiles. If modifications are detected, CLFS will deem the logfile as unsafe for parsing and return an error to the caller. CLFS is able to detect modifications by writing authentication codes to logfiles, which combines file data with a system-unique cryptographic key. A side effect of logfile authentication is that CLFS will fail to open logfiles that were created on other systems, as these logfiles contain authentication codes created using a system-unique cryptographic key. To open a logfile that was created on another system, an administrator must first use the "fsutil.exe clfs authenticate" command to correct the authentication codes. If you enable or do not configure this setting, CLFS will refer to local registry settings on whether logfile authentication should be done or not. By default, CLFS will do logfile authentication. The local registry settings for this feature can be found at "HKLM:\SYSTEM\CurrentControlSet\Services\CLFS\Authentication". If you disable his setting, CLFS will no longer perform logfile authentication. Logfiles will be able to be moved and opened across systems without Administrative action. However, CLFS will open and parse all logfiles, including maliciously crafted logfiles that may compromise the system.
What it writes
- Hive
- HKEY_LOCAL_MACHINE
- Registry key
System\CurrentControlSet\Policies- Value name
ClfsAuthenticationChecking- 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
In Intune
Native Intune setting: Yes — Policy CSP
./Device/Vendor/MSFT/Policy/Config/FileSystem/ClfsAuthenticationCheckingFileSystem on Microsoft LearnADMX-backed: Windows ships this template, so it is set with the template's own values, without an import.Not yet in a released Windows build when Microsoft published these DDF files; Learn shows the release it shipped in.
From Microsoft's Policy CSP DDF files (DDF v2 Files, February 2026), read 18 Oct 2026.
Configure and deploy
Choose a state; the output below is generated from the template for exactly that.
Enabled · Computer · template defaults
Registry file (.reg)
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Policies]
"ClfsAuthenticationChecking"=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: Enable / disable CLFS logfile authentication
# Name: ClfsAuthenticationChecking
# Scope: Machine
# State: Enabled
# Source: FileSys.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Policies' -Name 'ClfsAuthenticationChecking' -PropertyType 'DWord' -Value 1
These deployment candidates come from the ADMX template; they are separate from the native CSP mapping above.
- 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)
./Device/Vendor/MSFT/Policy/Config/ADMX_FileSys/ClfsAuthenticationCheckingADMX SyncML candidate
<SyncML xmlns="SYNCML:SYNCML1.2">
<SyncBody>
<Replace>
<CmdID>1</CmdID>
<Item>
<Meta>
<Format>chr</Format>
<Type>text/plain</Type>
</Meta>
<Target>
<LocURI>./Device/Vendor/MSFT/Policy/Config/ADMX_FileSys/ClfsAuthenticationChecking</LocURI>
</Target>
<Data><enabled/></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: Enable / disable CLFS logfile authentication
# Name: ClfsAuthenticationChecking
# Scope: Machine
# State: Enabled
# Source: FileSys.admx
$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Policies' -Name 'ClfsAuthenticationChecking' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
$reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Policies\ClfsAuthenticationChecking') | Out-Null
}
if ($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 $propertyName -Force -ErrorAction SilentlyContinue
}
}
# Policy: Enable / disable CLFS logfile authentication
# Name: ClfsAuthenticationChecking
# Scope: Machine
# State: Enabled
# Source: FileSys.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Policies' -Name 'ClfsAuthenticationChecking' -PropertyType 'DWord' -Value 1
History 5 retained releases
- 25H2 · 1.029 Sep 2025
- Added in this release.
Template
- Internal name
ClfsAuthenticationChecking- Namespace
Microsoft.Policies.FileSys- Template file
FileSys.admx- Release
- Windows 11 25H2 · 1.0 · file set
de4e49983ebd651f…
Definition, editor controls and support
Definition
<policy class="Machine" displayName="$(string.ClfsAuthenticationChecking)" explainText="$(string.ClfsAuthenticationCheckingExplain)" key="System\CurrentControlSet\Policies" name="ClfsAuthenticationChecking" presentation="$(presentation.ClfsAuthenticationCheckingOptions)" valueName="ClfsAuthenticationChecking" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.FileSys:Filesystem" />
<supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_Windows_10_0_RS1" />
<enabledValue>
<decimal value="1" />
</enabledValue>
<disabledValue>
<decimal value="0" />
</disabledValue>
</policy>Editor controls
<presentation id="ClfsAuthenticationCheckingOptions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />Supported platforms and category
Microsoft.Policies.FileSys:category:Filesystem
<category displayName="$(string.Filesystem)" name="Filesystem" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.Windows:System" />
</category>
Microsoft.Policies.Products:product:MicrosoftWindows
sha256:4b3cb6917b5e5b7cd142c0157f10882786b3e9ee67c29fd7b8f4c6cb2eec5fe7
Microsoft.Policies.Windows:category:System
<category displayName="$(string.System)" explainText="$(string.System_Help)" name="System" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.Windows:definition:SUPPORTED_Windows_10_0_RS1
<definition displayName="$(string.SUPPORTED_Windows_10_0_RS1)" name="SUPPORTED_Windows_10_0_RS1" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<or>
<range minVersionIndex="13" ref="Microsoft.Policies.Products:MicrosoftWindows" />
</or>
</definition>
Microsoft.Policies.FileSys:category:Filesystem
<category displayName="$(string.Filesystem)" name="Filesystem" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.Windows:System" />
</category>
<strings><string id="Microsoft.Policies.FileSys:Filesystem">Filesystem</string></strings>
Microsoft.Policies.Products:product:MicrosoftWindows
<product displayName="$(string.MicrosoftWindows)" name="MicrosoftWindows" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<majorVersion displayName="$(string.MicrosoftWindows2000)" name="MicrosoftWindows2000" versionIndex="1">
<minorVersion displayName="$(string.MicrosoftWindows2000_RTM)" name="MicrosoftWindows2000_RTM" versionIndex="0" />
<minorVersion displayName="$(string.MicrosoftWindows2000_SP1)" name="MicrosoftWindows2000_SP1" versionIndex="1" />
<minorVersion displayName="$(string.MicrosoftWindows2000_SP2)" name="MicrosoftWindows2000_SP2" versionIndex="2" />
<minorVersion displayName="$(string.MicrosoftWindows2000_SP3)" name="MicrosoftWindows2000_SP3" versionIndex="3" />
<minorVersion displayName="$(string.MicrosoftWindows2000_SP4)" name="MicrosoftWindows2000_SP4" versionIndex="4" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsXP)" name="MicrosoftWindowsXP" versionIndex="2">
<minorVersion displayName="$(string.MicrosoftWindowsXP_RTM)" name="MicrosoftWindowsXP_RTM" versionIndex="0" />
<minorVersion displayName="$(string.MicrosoftWindowsXP_SP1)" name="MicrosoftWindowsXP_SP1" versionIndex="1" />
<minorVersion displayName="$(string.MicrosoftWindowsXP_SP2)" name="MicrosoftWindowsXP_SP2" versionIndex="2" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsServer2003)" name="MicrosoftWindowsServer2003" versionIndex="3">
<minorVersion displayName="$(string.MicrosoftWindowsServer2003_RTM)" name="MicrosoftWindowsServer2003_RTM" versionIndex="0" />
<minorVersion displayName="$(string.MicrosoftWindowsServer2003_SP1)" name="MicrosoftWindowsServer2003_SP1" versionIndex="1" />
<minorVersion displayName="$(string.MicrosoftWindowsServer2003_R2)" name="MicrosoftWindowsServer2003_R2" versionIndex="2" />
<minorVersion displayName="$(string.MicrosoftWindowsServer2003_SP2)" name="MicrosoftWindowsServer2003_SP2" versionIndex="3" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsVista)" name="MicrosoftWindowsVista" versionIndex="4">
<minorVersion displayName="$(string.MicrosoftWindowsVista_RTM)" name="MicrosoftWindowsVista_RTM" versionIndex="0" />
<minorVersion displayName="$(string.MicrosoftWindowsVista_SP1)" name="MicrosoftWindowsVista_SP1" versionIndex="1" />
</majorVersion>
<majorVersion displayName="$(string.WindowsServer2008)" name="WindowsServer2008" versionIndex="5">
<minorVersion displayName="$(string.WindowsServer2008_RTM)" name="WindowsServer2008_RTM" versionIndex="0" />
<minorVersion displayName="$(string.WindowsServer2008_R2)" name="WindowsServer2008_R2" versionIndex="1" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows7)" name="MicrosoftWindows7" versionIndex="6">
<minorVersion displayName="$(string.MicrosoftWindows7_RTM)" name="MicrosoftWindows7_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsServer8)" name="MicrosoftWindowsServer8" versionIndex="7">
<minorVersion displayName="$(string.MicrosoftWindowsServer8_RTM)" name="MicrosoftWindowsServer8_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows8)" name="MicrosoftWindows8" versionIndex="8">
<minorVersion displayName="$(string.MicrosoftWindows8_RTM)" name="MicrosoftWindows8_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_RT)" name="MicrosoftWindows_RT" versionIndex="9">
<minorVersion displayName="$(string.MicrosoftWindows_RT_RTM)" name="MicrosoftWindows_RT_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsServer_6_3)" name="MicrosoftWindowsServer_6_3" versionIndex="10">
<minorVersion displayName="$(string.MicrosoftWindowsServer_6_3_RTM)" name="MicrosoftWindowsServer_6_3_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_6_3)" name="MicrosoftWindows_6_3" versionIndex="11">
<minorVersion displayName="$(string.MicrosoftWindows_6_3_RTM)" name="MicrosoftWindows_6_3_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_6_3_RT)" name="MicrosoftWindows_6_3_RT" versionIndex="12">
<minorVersion displayName="$(string.MicrosoftWindows_6_3_RT_RTM)" name="MicrosoftWindows_6_3_RT_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsServer_10_0)" name="MicrosoftWindowsServer_10_0" versionIndex="13">
<minorVersion displayName="$(string.MicrosoftWindowsServer_10_0_RTM)" name="MicrosoftWindowsServer_10_0_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_10_0)" name="MicrosoftWindows_10_0" versionIndex="14">
<minorVersion displayName="$(string.MicrosoftWindows_10_0_RTM)" name="MicrosoftWindows_10_0_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_10_0_RT)" name="MicrosoftWindows_10_0_RT" versionIndex="15">
<minorVersion displayName="$(string.MicrosoftWindows_10_0_RT_RTM)" name="MicrosoftWindows_10_0_RT_RTM" versionIndex="0" />
</majorVersion>
</product>
<strings><string id="Microsoft.Policies.Products:MicrosoftWindows">Windows operating system</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000">Windows 2000 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_RTM">Windows 2000</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP1">Windows 2000 Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP2">Windows 2000 Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP3">Windows 2000 Service Pack 3</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP4">Windows 2000 Service Pack 4</string><string id="Microsoft.Policies.Products:MicrosoftWindows7">Windows 7 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows7_RTM">Windows 7</string><string id="Microsoft.Policies.Products:MicrosoftWindows8">Windows 8 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows8_RTM">Windows 8</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003">Windows Server 2003 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_R2">Windows Server 2003 R2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_RTM">Windows Server 2003</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_SP1">Windows Server 2003 Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_SP2">Windows Server 2003 Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer8">Windows Server 2012 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer8_RTM">Windows Server 2012</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_10_0">Windows Server 2016 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_10_0_RTM">Windows Server 2016</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_6_3">Windows Server 2012 R2 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_6_3_RTM">Windows Server 2012 R2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista">Windows Vista operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista_RTM">Windows Vista</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista_SP1">Windows Vista Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP">Windows XP operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_RTM">Windows XP</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_SP1">Windows XP Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_SP2">Windows XP Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0">Windows 10 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RT">Windows 10 RT operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RTM">Windows 10</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RT_RTM">Windows 10 RT</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3">Windows 8.1 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RT">Windows RT 8.1 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RTM">Windows 8.1</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RT_RTM">Windows RT 8.1</string><string id="Microsoft.Policies.Products:MicrosoftWindows_RT">Windows RT operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_RT_RTM">Windows RT</string><string id="Microsoft.Policies.Products:WindowsServer2008">Windows Server 2008 operating systems</string><string id="Microsoft.Policies.Products:WindowsServer2008_R2">Windows Server 2008 R2</string><string id="Microsoft.Policies.Products:WindowsServer2008_RTM">Windows Server 2008</string></strings>
Microsoft.Policies.Windows:category:System
<category displayName="$(string.System)" explainText="$(string.System_Help)" name="System" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Windows:System">System</string><string id="Microsoft.Policies.Windows:System_Help">Allows configuration of various system component settings.</string></strings>
Microsoft.Policies.Windows:definition:SUPPORTED_Windows_10_0_RS1
<definition displayName="$(string.SUPPORTED_Windows_10_0_RS1)" name="SUPPORTED_Windows_10_0_RS1" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<or>
<range minVersionIndex="13" ref="Microsoft.Policies.Products:MicrosoftWindows" />
</or>
</definition>
<strings><string id="Microsoft.Policies.Windows:SUPPORTED_Windows_10_0_RS1">At least Windows Server 2016, Windows 10 Version 1607</string></strings>