A few days ago, a configuration profile disguised as an app called TweakBox, popped up on my brother's MacBook. He repeatedly attempted to delete it permanently, but it always magically reinstalls itself. Now the "virus" is on his phone too, and also seems to not be possibly deleted. This app/configuration profile does absolutely nothing, but it's annoying to have it pop up continuously. How can I remove it from both MacOS and iOS?
Good news is it's not a virus.
Bad news is it sounds like he's been trying to install some hacked/cracked apps! https://www.tweakboxapp.com
So you'll need to remove the TweakBox App (from home screen) and the TweakBox Profile (Settings > General > Profiles) that is installing it. Profiles can be shared between devices by iCloud so that's probably why he's seeing it on his laptop too.