So when I thought I was going to install a game from an APK file, I instead installed an app with no name which was unintentional. Ever since I've installed it, pop-ups appear from nowhere. Usually when I get on my phone after not using it. Here's a screenshot: I can't disable the app or uninstall it, and it's stuck on my phone. None of the antivirus or antimalaware apps I tried found any issues related to this app. I tried CM Security, Avast, and Malwarebytes. I gave as many details as possible. What to do?