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    How do Data Loss Prevention (DLP) Policies Work in Office 365?

    Data Loss Prevention (DLP) in Office 365 detects sensitive information by using deep content analysis. It can identify sensitive data without affecting people who work with the rest of the content.

    Once created, DLP Policies are stored and synchronized to content sources such as:

    • Exchange Online
    • OneDrive for Business
    • SharePoint Online Sites
    • Office 2016 desktop programs

    After they’re synchronized, these policies will start to enforce the required actions.

    What Does a Data Loss Prevention (DLP) Policy Contain?

    Office 365 includes definitions for sensitive information that are unique to different countries. This information can be credit card numbers, bank account numbers, and passport numbers.

    Each sensitive type can be keywords, internal functions, regular expressions, or pattern matches. This helps DLP detection achieve the highest degree of accuracy while also reducing the number of false positives that can interrupt people’s work. DLP policies allow for detection of different types of content within a single policy.

    How to Create a Data Loss Prevention Policy

    To create a DLP policy, first log into the Office 365 tenant, select Admin centers and then choose Security & Compliance.

    How to Create a Data Loss Prevention Policy

    Once the Security & Compliance center is loaded, expand the Data loss prevention menu and choose the Policy menu item.

    How to Create a Data Loss Prevention Policy

    Select the Create a policy button. A wizard interface will load from the right side, where you can set the properties needed for the policy. Choose the industry regulation category, which will display regional and country specific regulations.

    How to Create a Data Loss Prevention Policy

    Clicking the Financial option will display country specific policies that you can use.

    How to Create a Data Loss Prevention Policy

    Clicking a regulation will display a short description and the information it protects.

    How to Create a Data Loss Prevention Policy

    Once selected, click the next button and type the name and description for the policy, then press next. Not every location warrants a policy. You either select “All locations” or pick the locations that you want the policy to apply. You can decide between Exchange email, SharePoint sites, and OneDrive accounts. For SharePoint and OneDrive sites, you can choose sites or accounts as well as exclude some as needed.

    How to Create a Data Loss Prevention Policy

    Once you have defined the locations, press the next button. Now you can either choose the simple or advanced option. Simple settings make it easy to create the most types of DLP policies without creating rules. Advanced settings use the rule editor to give you control over every setting of your policy. The simple setting option covers most common scenarios.

    Even with the simple option, you still need to choose the detection type for the policy you are creating.

    How to Create a Data Loss Prevention Policy

    Once you choose whether to inspect external or internal content, press the next button. You will need to define policy tips for the end-users. Then, you can set an alert for the number of times a sensitive information type is shared with the same content. Finally, chose whether or not to block people from sharing and restrict access to the content.

    How to Create a Data Loss Prevention Policy

    You can turn the rule on right away, test it, and show or hide policy tips, or simply not enable it at all.

    How to Create a Data Loss Prevention Policy

    The End-user Experience

    Once you have created and enabled DLP policies, it will start to inspect content. For content within SharePoint or OneDrive for Business, any content that matches the policy is marked with both an icon and changes. It can display policy tips if you allowed them within the policy.

    How to Create a Data Loss Prevention Policy

    The hover panel for the items will display the policy and indicate if it’s blocked.

    How to Create a Data Loss Prevention Policy

    When a user clicks the View policy tip, he will see the policy details. He can fix the problem with the resolve button. Fixing the problem overrides the current violation and marks it as normal content.

    This is useful for notifying the end-user with alerts if configured within the policy itself. It also makes changes to the presentation of the content so that it is obvious that it’s in violation.

    After you create and turn on DLP policies, you need to verify that they’re helping you stay compliant. With DLP reports, you can view the number of policies and rules that match over time, and the number of false positives and overrides. You can filter those matches by location, time frame, and even narrow it down to a specific policy, rule, or action. With DLP reports, you can get business insights and:

    • Focus on specific time periods and understand the reasons for spikes and trends.
    • Discover business processes that violate your organization’s compliance policies.
    • Understand any business impact of the DLP policies.

    As well, you can use the DLP reports to fine tune your DLP policies as you run them.