Various security warnings affecting blog

There appears to be some sort of virus on my Word Press Blog – in Firefox and Safari a mesesage pops up that says “An update from http://www.update-java.net is requesting unrestricted access to your computer” I’ve looked at the web address and it is titled ‘CRIME BOSS’ with a login !!

On IE, the message is different – it says “This website has been reported as unsafe” and then continues to tell you about various threats. This one I looked up in Google and found that it may be the computer is infected with a rogue antispyware program called AV Security Suite.

There is also another security warning which I have seen this morning in IE and Firefox from http://delivery.etc.br.

I have checked the header code and I can’t see any rogue code that I don’t think should be there, I’ve also deleted a couple of plugins which I hadn’t installed.

I’m at a bit of a loss with this, any help would be much appreciated.

Thanks,
Rachel