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Microsoft updates Defender definitions for Windows and Server installation images

Feeds.4Sysops •IT News • June 6, 2026

Microsoft has released a new update package designed to refresh the security definitions and engine within Windows installation images. These updates target WIM and VHD files as well as ISOs used for deploying operating systems across the network. By integrating these patches into the installation media, the protection gap that exists between the initial OS setup and the first online update is significantly reduced. Source

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Microsoft Updates Defender Definitions for Windows Installation Images Microsoft has released a new update package for Windows Defender, aimed at refreshing security definitions and the anti-malware engine within Windows installation images. This update targets WIM, VHD files, and ISOs used for deploying Windows 10 and Windows 11 operating systems. The update addresses the protection gap that exists between the initial OS setup and the first online update, which can expose users to potential security risks. The latest security intelligence update version 1.451.297.0 was released, enhancing malware detection capabilities against threats such as trojans, ransomware, and backdoor exploits. Affected systems include Windows 11, Windows 10 ESU, and various Windows Server versions. This update is crucial for ensuring that new installations are equipped with the latest anti-malware definitions, thereby improving overall security and performance. 2 sources 28

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Platforms (2)

Windows Windows Server