Microsoft announced on Monday that Microsoft Defender Application Guard for Office is now at the public preview stage.
The solution, also called “Application Guard for Office,” adds a virtualized container or “sandbox” for users of Microsoft 365 productivity applications, such as Excel, PowerPoint and Word. It lets end users safely view and open attached Microsoft 365 application files in e-mails. Any scripts (macros or ActiveX controls) or malicious links in those files, when activated, don’t escape the sandbox. The solution will “isolate untrusted documents away from the system,” Microsoft explained in a document on the topic.
Application Guard for Office, while seemingly useful for all Office users, is just aimed at top-tier Microsoft 365 E5 plan subscribers. The licensing requirements for the product, when generally released, will be subscriptions to “Microsoft 365 E5 or Microsoft 365 E5 Security” licensing.
End users get a warning pop-up box when documents get opened using Application Guard for Office. An opened document will show another pop-up notice in the ribbon menu, and there will be a shield icon displayed in the taskbar. However, it’s still possible for end users to remove the Application Guard for Office protection on a document if they trust the source.
In addition, it’s possible for users to save a copy of an untrusted file, which lets them work on it in the container. Untrusted files from outside the organization appear as “read-only” files to end users.
IT pros can set certain policies for Application Guard for Office, such as disabling copy-and-paste actions, restricting printing and turning off app access to a device’s microphone and camera.
When Application Guard for Office reaches general availability, it’ll be turned off by default for Microsoft 365 E5 tenancies, the announcement indicated. A listing in the Microsoft 365 Roadmap showed Application Guard for Office getting a product release in December.
Requirements for testing the preview include having Windows 10 version 2004 (build 19041) Enterprise edition and Office 365 version 2008 (build 16.0.13212 or later). In addition, security update KB4566782 needs to be installed. There’s also hardware requirements for client devices, such as Intel Core i5 or equivalent at minimum, 8GB of RAM and 10GB of storage space.