When I woke up my computer there was a message to download the latest version of Adobe Flash. I did and the installer downloaded two other apps: Advanced Mac Cleaner and Megabackup. Should I be concerned?
Are you 100% sure you were seeing an Adobe update message?
I have had personal experience with visiting a web page that put up a message that was not really from Adobe, it was from a sponsor of that page who was using a "real looking" message to piggy-back their own software on an update to some other software