Hi,
There is nothing on Lush that will ever cause any malware or nasties on your system. We even check advertiser's links. I hate even linking to sponsors who have popups.
A member wrote earlier and said he was seeing double underline links on Lush, and it was causing all kinds of problems - he has some kind of spyware on his pc from the looks of things.
Here are some programs recommended by Gav and others, it is a good idea to check your system regularly, whether you are having problems or not - these are all FREE (or were at the time of writing) - avoid any program with "trial" mentioned anywhere, they invariably will not remove any nasties they find unless you pay for it, and there are plenty of free ones that work well:
http://www.superantispyware.com/
http://www.malwarebytes.org
http://spybot.softpedia.com/
http://www.lavasoft.com/products/ad_aware.php
http://www.microsoft.com/security_essentials/
Many are listed here too: http://www.thefreecountry.com/security/spywareremoval.shtml
Please share with the community any others not listed here, that you recommend.
Nicola