All you Mac users out there should be extra cautious as you surf the web. There are several new variants of a Trojan horse out there targeting Mac OS X 10.4 and 10.5 users. Make sure your anti-virus software is up to date.
Distributed as a compiled AppleScript called ASthtv05 or as an application, the Trojan allows remote access to the system and can transmit system and user passwords. SecureMac also said the Trojan is also capable of logging keystrokes and turning on file sharing.