Unwanted Apps or Virus or Malware installed silently

[dvinodeluru]

I am getting these apps/virus/malware install silently in background even the option is off auto-install in google play store settings and in device settings.

Not sure what these are and didn't find in internet search, except the mbigstone

mbigstone use to prompt now after when connected to wifi it auto instaaled and now its not going even it got install on mobile data.

Earlier i got the xhelper, i am able to figure out the auto installing background when in WiFi not on Mobile Data, and now for these are getting install on Mobile data.

xhelper gone after uninstall and not connected to wifi and mobile data for few days,