Files from the Internet zone must be opened in Protected View.

This policy setting allows you to determine if files downloaded from the Internet zone open in Protected View. If you enable this policy setting, files downloaded from the Internet zone do not open in Protected View. If you disable or do not configure this policy setting, files downloaded from the Internet zone open in Protected View.

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2016 -> Excel Options -> Security -> Trust Center -> Protected View "Do not open files from the Internet zone in Protected View" is set to "Not Configured" or "Disabled".

Procedure: Use the Windows Registry Editor to navigate to the following key:

HKCU\Software\Policies\Microsoft\Office\16.0\excel\security\protectedview

Criteria: If the value DisableInternetFilesInPV is REG_DWORD = 0, this is not a finding. If the value does not exist, this is not a finding. If the value is REG_DWORD = 1, then this is a finding.

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2016 -> Excel Options -> Security -> Trust Center -> Protected View "Do not open files from the Internet zone in Protected View" to "Not Configured" or "Disabled".