Dave has a Samsung Galaxy Tab and he's worried it may have malware. He's getting strange popups. Leo says it's possible, since Android is more porous to malware than iOS is. If he hasn't updated it lately, that could be part of the problem. Leo suggests backing up the data on the tablet and doing a factory reset. He'll have to reinstall all of his apps, but Leo suspects that a rogue app is the problem. Then he can reinstall them one at a time until the culprit reveals itself. There's also a tab for "my apps" in the Play Store, and apps he's installed previously, so he can install them from there.
If he doesn't want to be that radical, he can go in and remove any recent apps. It's likely something he downloaded recently.