Highjack?

Hi gang: While this is not an obvious php question, it does deal with security which is a concern. Just this morning had a couple of my sites "highjacked". What I found was someone had replaced my root level index.php with their own index.php. You can see the result at: http://xn--u2g.com/index1.php It was not a terrible loss nor inconvenience, but I wonder how they did it. Any ideas how this was done and suggestions as to how to prevent this from happening again? Thanks, tedd -- ------- http://sperling.com http://ancientstones.com http://earthstones.com