A Trojan Horse application that affects Mac users has surfaced on the Web, reports The Mac Observer. “What amounts to a proof-of-concept trojan horse application for the Mac started circulating around the Internet on Thursday. Ambrosia Software’s Andrew Welch detailed the trojan, which he dubbed the ‘Oompa-Loompa Trojan,’ in the company’s support forums. The malware-style application attempts to trick unsuspecting users into thinking that it is a JPEG image. If launched, the application requires administrator access before it can install files that attempt to send copies of itself to people that are in your iChat Buddy list.”