Redirect hack

Hi there
I'm using Defender and it seems great. However I've discovered that what looks like it might be a version of what I believe is the WP Pharma hack is running on my site - there are more than a thousand fake redirects pointing at pharmaceutical products, eg http://www.mysite.com/buy-cialis-online-from-canada/. I have no idea where or how these redirects are living or how to clean them out. Can Defender help tackle this??

(You can see a full list of the pharma redirects I know about here: https://www.google.co.uk/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=site%3Awww.wansteadium.com%20buy%2Bonline but I don't recommend clicking on any of the resulting sites...)