Pop up: "app_updater" will damage your computer. You should move it to the Trash.

The first and second screen shot are the same. There are 2 LaunchAgents folder and one has the "~" in front. Add the missing screenshot first so all the bad files can be removed at the same time. The location of each LauchAgents folder is:

/Library/LaunchAgents

~/Library/LaunchAgents

Everything in there looks good, have you deleted any files from those locations already? If you have deleted any files, make sure to restart your computer again. For other users who have had the same message, there was a file in your last screenshot called "com.app_updater.plist.

If you have not deleted anything and your are still seeing that message, post a screenshot at >System Settings > General > Login Item. Every time the "damage your computer" message has come up for other users, it was a file in one of those 3 locations, so it would surprise me to see anything wrong with your log in items, but the is the next best place to look.