Macs are safe from the Mimail worm currently plaguing PC users across America, a leading computer security expert says

The W32/Mimail-A worm means infected mail contains a false sender address that appears to come from the recipient's technology staff, according to Moscow-based security company Kaspersky Labs International, which believes Mimail is the work of Russian virus writers.

If the user opens the attached HTML file, the built-in Java script copies itself onto disk files, and then releases a carrier-file that is launched every time the computer is rebooted.

The message in the email reads: "Hello there, I would like to inform you about important information regarding your email address. This email address will be expiring. Please read attachment for details. Best regards, Administrator." It also has an attached file:

California-based McAfee Security says the worm can determine if the infected system is connected to the Internet by trying to contact, after which it begins emailing itself to other users.

However, leading IT security consultantcy Sophos Anti Virus has reassured Mac and Unix users that they can't be infected by the W32/Mimail-A worm.

Senior Sophos technology consultant Graham Cluley said: "The Mimail worm relies upon a vulnerability in Microsoft applications which is simply not present on Macs and Unix-based computers."