If you run a web site, and that site uses a database such as MySQL, then you need to know about a newly-discovered security problem. Around half a million web sites have been hit so far, by an attack which uses code injection techniques to amend the content of your database and thus change the content of your web pages.
The attack results in your web pages being amended to include a link to a web site called lizamoon. It's easy to find out if your site has been compromised, simply by using Google to search for combinations of your site name and lizamoon.
As you can see from the Google results below, it will be fairly obvious if your site has been hacked to include a link to the lizamoon site.
Note: The precise nature of the lizamoon dot com site is not yet known. We recommend that you DO NOT visit it in order to find out.