Cheap Android phones and tables often have built-in advertisement from manufacturer. One example of such software, it creates a window with Google Ads on top of

Cheap Android phones and tables often have built-in advertisement from manufacturer. One example of such software, it creates a window with Google Ads on top of browser window. The window is shown only when the browser is active to make it look like the ads is a part of the site. The ads appears only couple weeks after activation so that the user thinks it is a result of installation of some app and Youtube reviewers do not notice existence of malware. The adware consults a remote config which defines in what countries it should work. Another adware component automatically downloads and re-installs it if it is deleted. I found all these details through examining the official firmware image and reverse engineering. I don't remember if I reported Google Ads id to Google. It is interesting that Google doesn't notice and care about such use of their products.