Ah, but mobile devices are usually hidden behind a providers NAT and nearly all applications that are interactable and could be semi-directly contacted (eg. mes

Ah, but mobile devices are usually hidden behind a providers NAT and nearly all applications that are interactable and could be semi-directly contacted (eg. messaging apps) are written in a managed language, so a spread like we've seen with WCry is less likely to happen. Having said that, have you seen the amount of malware hiding in advertisements for Android? There's a lot.