April 1 may have come and gone, but plenty of computers still carry the Conficker worm, and now there’s some new evidence that it’s busy downloading a fake antivirus tool which pops up on your screen and promises to protect your computer for only $49.95. At the same time, it’s stealing your passwords and joining your machine up to a zombie botnet.

So the best idea is to get rid of it, permanently. This site has a great "eye chart" which will tell you if you’ve got the worm, and here are plenty of resources to help you get rid of it…properly.