I currently have a 1 year license for Dr.Web Security Space Life and so far, so good.
Dr.Web correctly detects and identifies those malwares that comes pre-installed on many Chinese smartphones (Doogee, Bluboo, etc), and none of the first three in the list, can do that (I've tried them all). The other antimalware that detects the chinese bugs is Malwarebytes. Period.
But according to this article, LG, Samsung, ZTE and Lenovo have presented malware pre installed too:
Over 30 different Android smartphones and tablets have been found to have had malware preinstalled on them before users even switched them on.