Spam Embedded – tips to find the hacked code

Hey guys
So my site appearently has been hacked. All looks fine on the outside, and when you dig into the code, it still looks fine.

The problem lies in the google cache. The hackers have found a way for these viagra ads to appear only in google search, which is a threat to my ranking and has had my site flagged as potentially compromised.

When I inspect the cached version in firebug http://webcache.googleusercontent.com/search?q=cache:jessicataylorkeller.com/ I can find the line of code. Is there a way to track where it is embedded by firebug? (eg. from x plugin or from the theme files etc).

I have looked at numerous wordpress hack guides and have done all steps except start from scratch. Is there any way I can track this code down better?

I’d be willing to pay someone to do this but they need to know what they are doing and really know this sort of problem.

Thanks for any tips!