Some users report that this app is also installed some other apps without the owners permission, and it is impossible to remove it even with factory/hard reset. The reason for that is that this app manages to isolate its files from the main OS, and that regardless of deletion/uninstall always finds a way to reinstall itself. There are few reports of successful removal with some tools, but xHelper adjusts very quickly and disables all possible security programs.
I personally had the opportunity to try to repair an infected smartphone with this trojan, and despite all the methods known to me, removal was unsuccessful in all cases.
That is actually amazing. There is little to none or none viruses/trojan horses that were so hard to remove in past.
Google which is android creator, should intervene and remove it at all costs because its in their best intrest to keep android semi-secure.
I will dig into that, but this is great warning and wake up call that android devices are not meant to keep any bigger amount of BTC on them.