Malicious files that use the the scripting capability of Microsoft Media Player to infect Windows machines have emerged as the main threat detected on the machines of Apple users who have taken advantage of Sophos' recent offer of a freebie anti-malware scanner application.
The Windows-specific threat - identified by Sophos as ASDFDldr-A - typically comes in the form of maliciously constructed and padded media files that pose as music files from the likes of Lady Gaga and Madonna. It is only when these malicious files happen to be executed on Windows PCs that anything bad happens. Nonetheless it's better that these malicious media files are identified and removed than left lying around.
read more here:
http://www.theregister.co.uk/2010/11/18/mac_malware/
