I'm not be able to install MSI packages downloaded from the Microsoft Reference Source Code Center.
The package installs first a compressed file that gets decompressed by the custom action. The custom action is an executable copied to the temp folder. McAfee VirusScan Enterprise 8.7.0i prevents any program to be started from the temp folder.
How can I turn off this behavior?
By the way, McAfee VirusScan Enterprise protects its services, so I (as an administrator) am not be able to stop the services.
If you're the McAfee administrator, you can edit the policy to allow execution of the file. Otherwise, you'll need to contact that administrator.
If you open the "Viruscan Console" and open the properties for "Access Protection" you should be able to untick/deselect the option in "Common Standard Protection" for "Prevent Common programs from running files from the temp folder"