Zebra scanner is a simple AS Studio application to trace down trojan viruses. Trojans, description; A Trojan refers to a program that appears as something you may think is safe, but hidden inside is usually something harmful. The lure of Trojans is that you may download a game or a picture, thinking it's harmless, but once you double-click this file the virus gets to work. Zebra scanner is intended to search for applications, hidden behind another extension than 'app'. It checks if any of the files in the selected folder(s) has either the real extension '.app' or the file type 'APPL'.