Yesterday Intego issued a security alert which was little more than a software update announcement thickly veiled as a virus warning. Intego had just released updated virus definitions for VirusBarrier that protected Mac users against a conceptual Trojan horse that could theoretically affect Mac OS X. The Trojan horse, named MP3Concept (MP3Virus.Gen), would exploit a weakness in Mac OS X where applications can appear to be other types of files. The code would be encapsulated in the ID3 tag of an MP3 file but in reality would be a hidden application that could run on any Mac running Mac OS X.

This seems to have been just a clever ploy to sell copies of VirusBarrier, but if any reader has actually found a Mac infected with this Trojan, please comment below.

Intego claims this Trojan horse has the potential to do any of the following:

• Delete all of a user's personal files
• Send an e-mail message containing a copy of itself to other users
• Infect other MP3, JPEG, GIF or QuickTime files

But as Apple-X.net rightly points out, "This alert seems to be blown out of proportion. The only working code seems to be just a CONCEPT trojan for Mac OS X (especially since "concept" appears in the trojan's name). A Google groups thread has an actual working trojan that does not harm your computer, but just illustrates the 'vulnerability'."