If the recent attacks from MSBlast weren't enough for reeling antivirus vendors and PC users to deal with, now there is another bug in the wild bent on causing computer chaos.

Sobig.F is a more traditional virus than MSBlast, in that it comes as an email attachment. It works by picking up email addresses from a whole range of files on your computer, and sending itself out to them. Infected messages come with a variety of subject lines including:

Re: Thank you!
Thank you!
Re: Details
Re: Re: My details

Re: Approved
Re: Your application
Re: Wicked screensaver
Re: That movie

The email comes with an attachment and, once executed, it copies itself on to your hard drive and starts to propagate itself to other email addresses it finds. The PC Advisor mailboxes have already received several infected messages and the virus is said to be spreading fast. It is thought to have originated in Asia.

Antivirus specialist BitDefender has made a free removal tool available here. But if you are concerned about any messages you have received, delete them immediately and never open attachments from senders you don't know. Also keep your antivirus software up to date.