Comment by iguessthislldo

A year or so ago I had to speedrun turning on developer mode on Android because my grandma had somehow installed an app that did a ransomware-like fullscreen popup after about 10-20 seconds after bootup. Could've factory reset it and called it, but wanted to try to rescue it for my grandma. Used adb to figure out what app was doing it and removed it. I might be misremembering details, but I think one of the reasons it could do what it was doing was it was using Samsung-specific permissions, which Google shouldn't allow on the store. I reported the app and looks like it's gone now.