SCCM

Windows 10 Credential Guard is currently another hot topic considering cyber security. Credential Guard is a new feature in Windows 10 (Enterprise and Education edition) that helps to protect your credentials on a machine from threats such as pass the hash.

To be able to enable Credential Guard in Windows, you need to have virtualization enabled on the CPU in the BIOS. Virtualization is rarely enabled by default, and as such you will need to enable it manually (F1, enter BIOS, modify the setting) or better yet, find a solution to do so remotely and automatically.

I have created following script in Powershell, that initially enables virtualization in the BIOS (Note: We only use Lenovo laptops, hence this is made for Lenovo laptops only) and then apply the registry-keys to enable Credential Guard. All steps are logged into c:\Windows\EnableCredentialGuard.log

The script can be targeted to the proper Windows 10 versions through SCCM collections (I this example I only target W10 1607 and 1703, as these Windows 10 versions no longer require the Isolated User Mode feature when enabling Credential Guard, as it’s now embedded into the Hypervisor)

When deploying powershell script from SCCM, remember to create the program with a command line like this: powershell.exe -ExecutionPolicy Bypass -NoLogo -NonInteractive -NoProfile -WindowStyle Hidden -File .\CredentialGuard\Enable-VirtualizationCredentialGuard.ps1

<#
.SYNOPSIS
    Enable virtualization in Lenovo Bios and enable Credential Guard in Windows 10
.DESCRIPTION
    This script will only run on Lenovo computers. If run on Lenovo computer, the script will check if virtualization is enabled in BIOS. 
    If not, virtualization will be enabled in the process of enabling CredentialGuard.
    Also appends actions to logfile: EnableCredentialGuard.log
 
.NOTES
    FileName:    Enable-VirtualizationCredentialGuard.ps1
    Author:      Martin Bengtsson
    Created:     19-07-2017
#>

$Logfile = "C:\Windows\EnableCredentialGuard.log"

#Create LogWrite function
Function LogWrite
{
   Param ([string]$Logstring)

   Add-Content $Logfile -Value $Logstring
}

#Get computermanufacturer
$Lenovo = Get-WmiObject Win32_ComputerSystemProduct | Select-Object Vendor

#If not a Lenovo laptop, write to log and exit script
If ($Lenovo.Vendor -ne "Lenovo"){
    
    LogWrite "Not a Lenovo laptop - exiting script"
    Write-Warning -Message "Not a Lenovo laptop - exiting script" ; exit 1
}

Else {
    
    Write-Host -ForegroundColor Yellow "Collecting Lenovo_BiosSetting information" ; LogWrite "Collecting Lenovo_BiosSetting information"
    $VirtEnabled = Get-WmiObject -Class Lenovo_BiosSetting -Namespace root\WMI | Where-Object {$_.CurrentSetting -match "Virtualization*"} | Select-Object CurrentSetting

If ($VirtEnabled.CurrentSetting -eq "VirtualizationTechnology,Disable"){
    
    Write-Host -ForegroundColor Cyan "Virtualization disabled - trying to enable virtualization" ; LogWrite "Virtualization disabled - trying to enable virtualization"
    Try {
        (Get-WmiObject -Class Lenovo_SetBiosSetting -Namespace root\wmi).SetBiosSetting("VirtualizationTechnology,Enable")
        (Get-WmiObject -Class Lenovo_SaveBiosSettings -Namespace root\wmi).SaveBiosSettings()

    }
    Catch {
        Write-Host -ForegroundColor Cyan "An error occured when enabling virtualization in the BIOS" ; LogWrite "An error occured when enabling virtualization in the BIOS" ; exit 1
    }
    cls
    Write-Host -ForegroundColor Cyan "Virtualization Successfully enabled" ; LogWrite "Virtualization Successfully enabled"
    
}

#Add required registry key for Credential Guard
$RegistryKeyPath = "HKLM:\SYSTEM\CurrentControlSet\Control\DeviceGuard"
    If (-not(Test-Path -Path $RegistryKeyPath)) {
        Write-Host -ForegroundColor Yellow "Creating HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard registry key" ; LogWrite "Creating HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard registry key"
        New-Item -Path $RegistryKeyPath -ItemType Directory -Force
    }
    #Add registry key: RequirePlatformSecurityFeatures - 1 for Secure Boot only, 3 for Secure Boot and DMA Protection
    New-ItemProperty -Path $RegistryKeyPath -Name RequirePlatformSecurityFeatures -PropertyType DWORD -Value 1
    Write-Host -ForegroundColor Yellow "Successfully added RequirePlatformSecurityFeatures regkey" ; LogWrite "Successfully added RequirePlatformSecurityFeatures regkey"
    
    #Add registry key: EnableVirtualizationBasedSecurity - 1 for Enabled, 0 for Disabled
    New-ItemProperty -Path $RegistryKeyPath -Name EnableVirtualizationBasedSecurity -PropertyType DWORD -Value 1
    Write-Host -ForegroundColor Yellow "Successfully added EnableVirtualizationBasedSecurity regkey" ; LogWrite "Successfully added EnableVirtualizationBasedSecurity regkey"
    
    #Add registry key: LsaCfgFlags - 1 enables Credential Guard with UEFI lock, 2 enables Credential Guard without lock, 0 for Disabled
    New-ItemProperty -Path HKLM:\SYSTEM\CurrentControlSet\Control\Lsa -Name LsaCfgFlags -PropertyType DWORD -Value 2
    Write-Host -ForegroundColor Yellow "Successfully added LsaCfgFlags regkey" ; LogWrite "Successfully added LsaCfgFlags regkey"
    
    Write-Host -ForegroundColor Yellow "Successfully enabled Credential Guard - please reboot the computer" ; LogWrite "Successfully enabled Credential Guard - please reboot the computer"
    
}   

Snip of the logfile when everything succeeds:

Note: June 3 2018: This post will be updated as soon as possible with some minor changes and reflect how I do this today 🙂

In this blog post I will go into details about how I flash the BIOS of our Lenovo ThinkPad series during OSD using ConfigMgr.

First off you obviously need to download the latest BIOS from the Lenovo support site: http://support.lenovo.com/dk/en/. In this example I’m flashing the BIOS of a ThinkPad T450s.

Go ahead and locate and download the BIOS Update Utility for Windows. The most recent version as of now for T450s is 1.21:

When downloaded, extract the content to your source file library. In this case I have a folder structure equal to this: D:\Pkgsource\Applications\Lenovo\BIOS\T450S\1.21

The content of the 1.21 folder should be looking like this:

Next, mind the highlighted file: FlashBIOS.cmd. Create this file manually with following content (I exit the script with exitcode 0, as the BIOS update itself might return exitcodes seen as failures. Some might dislike this approach, but you can also translate the actual exitcode into zero using whatever method you prefer):

“%~dp0WINUPTP.exe” -s
exit 0

With this in place, go ahead and create a package in ConfigMgr with above content and distribute the package to your distribution points (I’m not going into details on this one, as this is pretty standard).

My packages in ConfigMgr looks like this (I have highlighted the package used in this example):

Next we will be using the package in our task sequence in a step of Run Command line. This is done somewhere after the step of Setup Windows and Configuration Manager like this (I put BIOS updates in the end of my task sequence as they require reboots):

As updating the BIOS to this specific version is a onetime operation, you would want to add following conditions to the Options tab:

This will make sure that the step is only run when a Lenovo Thinkpad T450 is being deployed AND when the BIOS is not already the most recent version (no need to run the step again, if the same laptop should be reinstalled in a near future)

You can run following powershell commands to display the computermodel and what BIOS version that currently is installed:

Get-WmiObject Win32_Computersystem

Get-WmiObject Win32_BIOS

Enjoy 🙂

I just updated my ConfigMgr environment to 1511 (CurrentBranch) and while the installation itself went safe and sound, following is to be noted:

• The new Software Center never got installed properly with a shortcut in the start menu (%ProgramData%\Microsoft\Windows\Start Menu\Programs\Microsoft System Center\Configuration Manager)
  I had to re-enable the setting in my Client Settings (Disable the feature, OK, Enable the feature, OK and do another policy refresh)

• None of the new Windows 10 1511 software updates was synced into SCCM. I checked WSUS manually, and the classification Upgrades was not selected regardless of the Upgrades being indeed selected in SCCM. To solve this, I had to de-select all classifications in SCCM and select them again on the Software Update point. When I checked the chosen classifications in WSUS again, the proper selections was inherited from SCCM as expected and the next sync downloaded the Windows 10 Upgrades.