One of the most tenacious blackhat webspam techniques we continue to see is hacked sites. I wanted to remind site owners that our free “Fetch as Google” tool can be a really helpful way to see whether you’ve successfully cleaned up a hacked site.

For example, recently a well-known musician’s website was hacked. The management firm for the musician wrote in to say that the site was clean now. Here’s the reply I sent back:

Unfortunately when our engineers checked this morning, the site was still hacked. I know the page looks clean to you, but when we send Googlebot to fetch www.[domain].com this morning, we see

<title>Generic synthroid bad you :: Canadian Pharmacy</title>

on the page. What the hackers are doing is sneaky but unfortunately pretty common. wgr55 . When you surf directly to the website, you see normal content. But when a search engine (or a visitor from a search engine) visits the website, they see hacked drug-related content. The reason that the hackers do it this way is so that the hacked content is harder to find/remove and so that hacked content stays up longer.

The fix in this case is to go deeper to clean the hack out of your system. See http://support.google.com/webmasters/bin/answer.py?hl=en&answer=163634 for some tips on how to do this, but every website is different.

One important tool Google provides to help in assessing whether a site is cleaned up is our “Fetch as Googlebot” feature in our free webmaster console at http://google.com/webmasters/ . That tool lets you actually send Googlebot to your website and see exactly what we see when we fetch the page. That tool would have let you known that the website was still hacked.

I hope that helps give an idea of where to go next.

Something I love about “Fetch as Googlebot” is that it’s self-service–you don’t even need to talk to anyone at Google to diagnose whether your hacked site looks clean.