Linden Lab's Grid Status just reported that a database issue which caused a folder called "Adam N Eve Avatars_OLD" to appear in users' Lost & Found inventory has been resolved. Earlier today, many users reported this, some openly worrying that it was a malicious virus. (A rumor that reportedly gained some traction throughout SL's various social media/in-world chat channels.) It wasn't a virus, Linden Lab claims, has been addressed, and if you still see that folder in your inventory, clearing you cache should fix it. Hat tip: Disa Marnesdottr, sachi Vixen.