I recently tried to send the black dot bug to Windows Phone that has crashed Apple’s imessage and whatsapp for android but it does nothing to Windows Phone, I will have to say the security of Windows Phone is very tight even than Apple’s iOS.
That's cool, but hackers and malware coders know that there aren't many WP users in the wild, so it's not worth their time and effort.
If a Windows phone falls in a forest and (of course) no one is around, does it make a noise?