Malware
xHelper
Xhelper is a very persistent malware that can reinstall itself after factory reset, Xhelper downloads malicious apps and displays annoying ads.
xHelper is a Android malware family.
Background
Xhelper is an exceptionally persistent piece of malware that is able to reinstall itself even after a factory reset. It pulls down malicious apps and bombards the user with intrusive ads.
Source: Malpedia (Fraunhofer FKIE).