This may have worked in 2014 where you could leave the option to 'allow for installation of apps outside the app store' enabled, these days the option is generally disabled unless the user deliberately enables it for the installation of one application at a time. Unlike Windows where Outlook will open anything and double extension hacks still exist, the simplest form of hack that appears impossible for Microsoft to resolve. Even UAC is absolutely bloody hopeless when it comes to privilege escalation and so called secure certificates appear to be getting stolen in a never ending cycle allowing software to install above that of super admin - Meaning the only way to remove it is a complete reformat and reinstall. Fact is, the worlds most popular OS suffers a minuscule amount of infections in direct comparison to Windows. So it's not purely popularity that's the reason for the ocean of infections under Windows.