Internal Browser Overlay over Chrome: Malware? How to remove?

[AC Question]

This issue applies to the phone of a friends child. So I only have limited details, as I don't have the phone at hand.

However, the symptoms: When you open Chrome, then another browser is opened on top of it, called "Browser" in the task manager. It is supposedly the internal android-browser, but I'm not sure. It is visible in the task manager and can be stopped there. It will however restart whenever you start chrome and will be placed on top of Chrome. It only shows a white page, sometimes it also shows a google-search-page. The white page may be the result of a running child-protection-software that blocks non-whitelisted pages. The child has supposedly turned off the child-protection immediately before the symptoms appeared for the first time.
Additionally the symptoms appear also randomly when you open other apps, mainly games. Maybe it is a general malware action, that always starts this "Browser" whenever a WebView (in game ads) or Browser is shown or url is requested. I don't know, so I'm looking forward to any hints from you:

* Is this a virus / trojan /... ? I think so.
* Do you have a hint, which one it could be?
* Do you even know, how to remove it?

Thanks in advance! Kind regards.