Dunno. From all reports about the earlier one, MAC Defender, it is necessary to kill the process in AM first before you are able to delete any of its components. Otherwise, when you try to delete it gave an "in use" message. Did you use the Filter, upper right corner of AM, set to All Processes?
You would want to trash the Application, the Login Item, also its Preference file (I believe, in your Home folder Library>Preferences, but check in HD Library>Preferences, also.) If you ran the istaller -- which perhaps you didn't and explains why you were able to delete it in Login Items, but I would have thought otherwise -- there would also be a receipt in /var/db/receipts. For that, use the Finder menu Go>Go to Folder and enter /var/db/. To trash it using Move to Trash, you will be prompted for your password. Check to see if there's anything in your Home folder>Library>Application Support.
You didn't mention deleting the Application, so I have the feeling you didn't get the full installation. Still, doesn't explain why you found it in Login Items.
Get EasyFind and search using both names. Should show you everything.
http://www.devon-technologies.com/products/freeware/