Check Point Threat Intelligence and research teams recently discovered a high volume Chinese threat operation which has infected over 250 million computers worldwide. The installed malware,  Fireball, takes over target browsers and turns them into zombies. Fireball has two main functionalities:  the ability of running any code on victim computers–downloading any file or malware, and  hijacking and manipulating infected users’ web-traffic to generate ad-revenue.

http://blog.checkpoint.com/2017/06/01/fireball-chinese-malware-250-million-infection/