In a recent interview with Matt Cutts (a popular software engineer from Google that handles Spam) on WebmasterRadio Matt noted that Google has run across a few sites that had been hacked and in a manner that wasn’t immediately apparent to the site owners. Jim Hedger wrote an article which summed up the entire interview and I highly recommend the read. For the purposes of this posting, however, I want to focus on how to determine whether your site has been hacked.

First of all, here is a little detail on the hack from Matt Cutts:
“… basically say, everytime someone fetches something, go fetch it through this CGI file. The CGI program does cloaking. It doesn’t just check the user-agent, it actually checks for their IP address as well. And if it’s GoogleBot, it will add links to porn sites. And here’s the really scary thing or it will take all your existing links, or some of your existing links and, will slap a NO FOLLOW on them. So, the hacker is basically saying, ‘All those sites you chose to link to, uh-uhh… we’re not going to link any PR that way, we’re going to link to our porn sites and that is just pretty much pure evil.'”

Identifying a Hacked Site
So how can you tell if your website is being affected by this cloaking hack? First of all Matt and his host Vanessa Fox (also from Google) goes to great lengths to note that this is a very rare hack so keep that in mind.

Here is the simplest way to discover whether your site (or your competition’s) is using cloaking:

  1. Ensure that you have the Google Toolbar installed and using the options button within the toolbar enable the tranlation option so that it appears on your toolbar. Note that you may need the newest version of the toolbar to do this (I am not 100% if it was added to previous versions).
  2. Visit the website you want to check.
  3. Click “Translate” (or “Translate into English” depending on your browser) and the page will be instantly translated into English from English.
  4. If what you see is different than your live site, you had better contact your webmaster immediately because your website might have been hacked.

How Does this Technique Work?
This translation process beats the anti-detection technology used by cloaking software so that you can see what Googlebot actually sees when it visits your website. This is a very effective method of testing your site but don’t forget to check your competitor’s as well. After all, you may find out that your competitor is purposely using cloaking to get ahead in search engine rankings. Cloaking is fiercely prohibited by search engines so you can expect your competitors will not get away with this for long. If it turns out they have been malisciously hacked I recommend letting them know, however it is ultimately up to your conscience whether you will inform them or not.