ZCryptor: Ransomware that spreads itself as a worm

Zcryptor is a hybrid, part ransomware and part worm. It encrypts files and copies itself onto external media.
Triada: organized crime on Android

Triada is a modular mobile Trojan that actively uses root privileges to substitute system files and uses several clever methods to become almost invisible
Acecard - the most dangerous Android banking trojan

Acecard is one of the most advanced banking trojans. It’s capable of overlaying more than 30 banks’ and financial systems’ apps and is spread via Google Play.