The main purpose of any business is to grow and be more successful – and that applies to criminal organizations just as much as it does to legitimate companies.  Cybercriminals have found that attacks specifically targeting smartphones and tablets, particularly those that incorporate a ransomware payload, are effective and profitable – which is why the volume of malware targeting users of mobile devices trebled during 2015.

http://blog.checkpoint.com/2017/06/08/chain-reaction-new-wave-mobile-attacks/