@Gina @fdroidorg No, of course the virus wasn't from F-Droid! But it wasn't from the Play Store either. I didn't bother asking her where it came from, she would be clueless. The 24 hours is the "advanced flow", see the red part of https://keepandroidopen.org/ . It's supposed to make it harder to fall for scams and malware, but inevitably it also makes it harder to install F-Droid and other legitimate apps from anywhere besides the Play Store.