The first hours of a newly installed Windows deployment can leave the system vulnerable because of a Microsoft Defender protection gap. This is because the OS installation images may contain outdated antimalware software binaries.
The devices on which these deployments are made are inadequately protected until they receive the first antimalware software update. We recommend that you regularly service OS installation images in order to update Microsoft Defender binaries and minimize this protection gap in new deployments.
This article describes antimalware update package for Microsoft Defender in the OS installation images (WIM and VHD files). This feature supports the following OS installation images:
Windows 10 (Enterprise, Pro, and Home editions)
Windows Server 2019
Windows Server 2016
After a new package version is released, support for the previous two versions will be reduced to technical support only.
Versions prior to the previous two versions will no longer be supported. For more information, see Manage Windows Defender Antivirus updates and apply baselines.
New version: 1.1.2109.01
This package updates the anti-malware client, anti-malware engine, and signature versions in the OS installation images to following versions:
Platform version: 4.18.2107.4
Engine version: 1.1.18400.5
Signature version: 1.347.891.0
The package size is approximately 115 MB.
Known issues in this update
This package includes monthly updates and fixes to the Microsoft Defender antimalware platform and engine that's used by Microsoft Defender Antivirus in Windows 10.
This package also includes the latest security intelligence update that is available up to the date of release.
How to obtain this update
Different update packages are required for different Windows OS image architectures. Select the architecture that matches the installation image to which you will apply this update:
Note: These links point to defender-update-kit-[x86|x64].zip. Extract this .zip file to get the Defender update package (defender-dism-[x86|x64].cab) and an update patching tool (DefenderUpdateWinimage.ps1) that assists the update operation for OS installation images.
Package update tool
The following prerequisites apply to running this patching tool (DefenderUpdateWinImage.ps1):
You must be running a 64-bit Windows 10 or later OS environment that includes PowerShell 5.1 or a later version.
The Microsoft.Powershell.Security and DISM modules must be installed.
You must start PowerShell on the device by using administrator privileges.
Do not use this package to update live images because it can damage the Windows installation that Is running inside the Virtual Machine.
The DefenderUpdateWinImage.ps1 tool provides an option to remove the update. However, you may still want to keep a backup copy of images before you apply the update.
How to apply this update
PS C:\> DefenderUpdateWinImage.ps1 - WorkingDirectory<path> -ActionAddUpdate - ImagePath <path_to_Os_Image> -Package <path_to_package>
How to remove or roll back this update
PS C:\> DefenderUpdateWinImage.ps1 - WorkingDirectory<path> -ActionRemoveUpdate - ImagePath <path_to_Os_Image>
How to list the details of installed update
PS C:\> DefenderUpdateWinImage.ps1 - WorkingDirectory<path> -ActionShowUpdate - ImagePath <path_to_Os_Image>
Learn about the terminology that Microsoft uses to describe software updates.