It's most likely not Google, probably something deliberately designed to look like and make you think it's Google.
It could be 2 things, an app you've installed with aggressive advertising (common culprits are cache cleaners, memory boosters, task killers, battery boosters, anything by Cheetah Mobile, anything by Go Dev team or anything by DU etc). That can be solved by finding and uninstalling the offending app.
Alternatively it could mean your browser has been hijacked which can be fixed by clearing the data and cache on any internet browsers you use. Clearing data means you'll lose bookmarks and login info you've entered, but a number of popular browsers have cloud or local backup so check before you clear data.