I'm running macOS 10.13.6 on my MBA. Suddenly in the last couple of weeks, if I try to delete a program, I get a prompt to enter my MBA password. Is this legit and a change from macOS before the latest upgrade? In additon, about a week ago I got a request to update Adobe Flash (which I've done in the past). Now it get flashes I may have a virus with offers to install anti virus software. I think this is bogus as well. Is there a virus alert out for macOS 10.13.6?