This happened to a wordpress blog I worked on last year. The version was a few years old and the hackers were able to add some code to footer.php that checked

This happened to a wordpress blog I worked on last year. The version was a few years old and the hackers were able to add some code to footer.php that checked the referrer and if it was Google, it displayed phentermine and cialis links. For regular visitors, it displayed the regular page. This way, when google crawled the site, the links were there, but when the web masters looked at it it was normal.