Look out for another christmas virus that is starting to find it's way to festive office workers. This is attached to an e-mailed christmas carol and it contains a damaging internet worm.

It is known as the I.worm.music, or W32/Music work and it first came out in September, only to re-appear last week as a friendly christmas e-mail with a christmas carol attached as an .exe file.

The music work carries the subject line 'Testing to send file' followed by one of two e-mail messages greeting users and saying that there is some music that they will like attached. It will copy itself to the Windows system directory using sysmcm.exe and registers in the auto-run registry. It also has the capability of downloading plug-ins from hostile websites to upgrade itself.

Even though it is thought to be capable of spreading quickly, the worm is more irritating than a threat but it is a good reason for people to be aware of these types of e-mails they could receive on the run-up to christmas.