All my sites on Hostgator got attacked by iframe hack

At 7 pm tonight my students emailed me that our blog was down. I checked immediately for an attack, and found that all the index.php and index.html files were altered an 18:46 EST, and a line of code was added either after the starting body tag or at the very end of the code <iframe src="" width=230 height=0 style="visibility: hidden"></iframe> do not go there... I googled the topic and found that some Russian hackers have created Keylogger