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1.8.7.2.8 Ensure 'VBA Macro Notification Settings' to Enabled (Disable all Except Digitally Signed)

Information

This policy setting controls how the specified applications warn users when Visual Basic for Applications (VBA) macros are present. If you enable this policy setting, you can choose from four options for determining how the specified applications will warn the user about macros: - Disable all with notification: The application displays the Trust Bar for all macros, whether signed or unsigned. This option enforces the default configuration in Office. - Disable all except digitally signed macros: The application displays the Trust Bar for digitally signed macros, allowing users to enable them or leave them disabled. Any unsigned macros are disabled, and users are not notified. - Disable all without notification: The application disables all macros, whether signed or unsigned, and does not notify users. - Enable all macros (not recommended): All macros are enabled, whether signed or unsigned. This option can significantly reduce security by allowing dangerous code to run undetected. If you disable this policy setting, 'Disable all with notification' will be the default setting. If you do not configure this policy setting, when users open files in the specified applications that contain VBA macros, the applications open the files with the macros disabled and display the Trust Bar with a warning that macros are present and have been disabled. Users can inspect and edit the files if appropriate, but cannot use any disabled functionality until they enable it by clicking 'Enable Content' on the Trust Bar. If the user clicks 'Enable Content', then the document is added as a trusted document. Important: If 'Disable all except digitally signed macros' is selected, users will not be able to open unsigned Access databases. Also, note that Microsoft Office stores certificates for trusted publishers in the Internet Explorer trusted publisher store. Earlier versions of Microsoft Office stored trusted publisher certificate information (specifically, the certificate thumbprint) in a special Office trusted publisher store. Microsoft Office still reads trusted publisher certificate information from the Office trusted publisher store, but it does not write information to this store. Therefore, if you created a list of trusted publishers in a previous version of Microsoft Office and you upgrade to Office, your trusted publisher list will still be recognized. However, any trusted publisher certificates that you add to the list will be stored in the Internet Explorer trusted publisher store. The recommended state for this setting is: Enabled. (Disable all Except Digitally Signed) By default, when users open files in Word that contain VBA macros, Word opens the files with the macros disabled, and displays the Trust Bar with a warning that macros are present and have been disabled. Users may then enable these macros by clicking Options on the Trust Bar and selecting the option to enable them. Disabling or not configuring this setting may allow dangerous macros to become active on user computers or the network.

Solution

To implement the recommended configuration state, set the following Group Policy setting to Enabled. User Configuration\Administrative Templates\Microsoft Word 2013\Word Options\Security\Trust Center\VBA Macro Notification Settings Impact: This configuration causes documents and templates that contain unsigned macros to lose any functionality supplied by those macros. To prevent this loss of functionality, users can install the macros in a trusted location, unless the Disable all trusted locations setting is configured to Enabled, which will block them from doing so. If your organization does not use any officially sanctioned macros, consider choosing No Warnings for all macros but disable all macros for even stronger security.

See Also

https://workbench.cisecurity.org/files/556

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-18(4)

Plugin: Windows

Control ID: 54c8d54501cf95a2ef4733b8227bb1e8474e9ccdc071acee7a6fead4e032b6bf