Microsoft Makes Endpoint Data Loss Prevention Generally Available

Windows 10 and Edge Deliver Signals for DLP Evaluation

Announced as Generally Available on November 10, Endpoint DLP is a Microsoft 365 offering which uses signals generated by actions performed on Windows 10 workstations to evaluate against DLP policies. Supported actions include copying files to removable media like a USB or to a network share, printing files, uploading to a cloud app, or copying data to the clipboard.

Microsoft leverages its control of Windows and Edge by avoiding the need to deploy additional agents to monitor activity on a workstation. The necessary code to detect actions and submit them for DLP evaluation is incorporated into Windows 10 (version 1809 or later) and recent versions of the Edge browser.

Edge is the preferred browser because it understands how to respect endpoint DLP policies, and you can block other browsers from accessing files protected by policies. For instance, you could block Chrome or Firefox from opening a Word document if a specific retention label is present.

Not an Office 365 Feature

Before you can use Endpoint DLP, you need Microsoft 365 E5 licenses or either the Microsoft 365 E5 information protection and governance or compliance add-ons. This is understandable given that Windows 10 is bundled in the Microsoft 365 suite. Being able to gather information from Windows is a big part of the Endpoint DLP value proposition and it’s important that users have access to builds of Windows which include the DLP code. Having a Microsoft 365 license makes it more likely that users will be current, and not run something like an old Windows 7 or Windows 8 device.

Workstations used by licensed accounts can be onboarded (enabled) through the Microsoft 365 compliance center to start the flow of signals for DLP evaluation, unless they are already enrolled for Windows Defender, in which case Endpoint DLP works without any further configuration.

Looking for Violations

Once a workstation is enabled, actions taken by the user are monitored for potential violations against policy using the same kind of conditions as used to monitor Office 365 activity. For example, attempts to upload documents containing credit card numbers can be detected and stopped. Supported file formats include Office documents, PDF, text, and source code.

Endpoint DLP settings for the organization can be adjusted in the Microsoft 365 compliance center (Figure 1) to reduce the amount of noise in signals by excluding certain folders like the recycle bin, temp folder, or folders used for non-work files. It’s also possible to allow uploads to specific cloud services without generating a violation. Policy thresholds can be set to generate alerts when a large number of similar events happen. For instance, a policy could alert administrators if someone prints more than twenty documents assigned the Confidential sensitivity label.

Checking Devices

When Endpoint DLP is available in a tenant, DLP policies can be created for a target location called Devices, just like choosing SharePoint or Exchange as policy locations. The normal approach is to separate device policies from those used with Office 365 workloads, but you can combine them. Device policies have separate settings for restrictions to enforce when conditions are met (Figure 2).

Signals to SIEM

Apart from being used by DLP, the signals generated by devices can be gathered and analyzed in a SIEM. An example using Azure Sentinel is described in this article.

Good for Some Organizations

Some organizations will like Endpoint DLP very much. Others will not be interested because of the cost of Microsoft 365 licenses, presence of non-Windows devices, or because they’ve invested in other solutions. In either case, this is an area that’s worth keeping an eye on because the signs are that Microsoft is taking advantage of its Information Protection, Office, and Windows assets to create a compelling unified DLP story.

For more independent information about Endpoint DLP, read this article by MVP Anders Onevinn.

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For more information about DLP for Office 365 workloads (Exchange, SharePoint, OneDrive, and Teams), read chapter 22 of the Office 365 for IT Pros eBook.