Microsoft recently announced the deprecation of Defender Application Guard for Office and the associated Windows Security Isolation APIs, redirecting users towards alternative security protocols. Defender Application Guard for Office was introduced as a security feature for Microsoft 365 Apps, specifically catering to Windows 10 and 11 Enterprise editions. Its primary function involved safeguarding against potential threats by confining files downloaded from untrusted sources within a secure sandbox, preventing access to trusted resources on the user’s device.
This mechanism leveraged hardware-based virtualization to shield devices from potential malware infections when opening downloaded documents in Office applications. In light of this deprecation, Microsoft emphasizes the adoption of other security measures such as Defender for Endpoint attack surface reduction rules, Protected View, and Windows Defender Application Control. The recommendation to transition away from Defender Application Guard for Office comes approximately two years after its roll-out to all Microsoft 365 customers with supported licenses.
Initially launched in November 2019 as part of a limited preview, this security feature was exclusively available to organizations with Microsoft 365 E5 or Microsoft 365 E5 Security licenses. Microsoft’s decision to phase out Defender Application Guard for Office signifies a strategic shift in its approach to bolstering security within the Office suite and Windows operating system. This move aligns with the tech giant’s ongoing efforts to optimize security measures, recommending alternative protocols while acknowledging the evolution of threats and the necessity for adaptable defense mechanisms in the digital landscape.
