I have a client site whose listing on Google is now an ad for cialis and other pharmaceutical favorites of spammers. When clicked, it still leads to my clients' site, and all of the page links underneath the main listing are all correct. The rest of the site looks fine and is working fine. And this only happens on Google; not on any other search engines.
I'm primarily a designer, so identifying inserted code is not my strong point. I'm about to change all of the passwords for the site, reinstall WP, reinstall a backed-up (and slightly older) version of the theme, but if anyone has seen anything like this, I'd really appreciate some advice.