Microsoft Internet Explorer Mouse Tracking

Type packetstorm
Reporter Nick Johnson
Modified 2012-12-11T00:00:00


                                            `Summary: Unprivileged attackers can track your system-wide mouse  
movements from any IE page, even when the page is unfocused or  
Package: Microsoft Internet Explorer  
Affected: Tested on versions 6–10  
A security vulnerability in Internet Explorer, versions 6–10, allows  
your mouse cursor to be tracked anywhere on the screen, even if the  
Internet Explorer window is inactive, unfocused or minimised. The  
vulnerability is notable because it compromises the security of  
virtual keyboards and virtual keypads.  
As a user of Internet Explorer, your mouse movements can be recorded  
by an attacker even if you are security conscious and you never  
install any untoward software. An attacker can get access to your  
mouse movements simply by buying a display ad slot on any webpage you  
visit. This is not restricted to lowbrow porn and file-sharing sites.  
Through today’s ad exchanges, any site from YouTube to the New York  
Times is a possible attack vector. Indeed, the vulnerability is  
already being exploited by at least two display ad analytics companies  
across billions of webpage impressions each month. As long as the page  
with the exploitative advertiser’s ad stays open—even if you push the  
page to a background tab or, indeed, even if you minimise Internet  
Explorer—your mouse cursor can be tracked across your entire display.  
Details of the vulnerability  
Internet Explorer’s event model populates the global Event object with  
some attributes relating to mouse events, even in situations where it  
should not. Combined with the ability to trigger events manually using  
the fireEvent() method, this allows JavaScript in any webpage (or in  
any iframe within any webpage) to poll for the position of the mouse  
cursor anywhere on the screen and at any time—even when the tab  
containing the page is not active, or when the Internet Explorer  
window is unfocused or minimized. The fireEvent() method also exposes  
the status of the control, shift and alt keys.  
Affected properties of the Event object are altKey, altLeft, clientX,  
clientY, ctrlKey, ctrlLeft, offsetX, offsetY, screenX, screenY,  
shiftKey, shiftLeft, x and y.  
<!DOCTYPE html>  
<meta charset="utf-8" />  
<title>Exploit Demo</title>  
<script type="text/javascript">  
window.attachEvent("onload", function() {  
var detector = document.getElementById("detector");  
detector.attachEvent("onmousemove", function (e) {  
detector.innerHTML = e.screenX + ", " + e.screenY;  
setInterval(function () {  
}, 100);  
<div id="detector"></div>  
A demonstration of the security vulnerability may be seen here:  
The implications for virtual keyboards and virtual keypads  
We have created a game to illustrate how easily this security  
vulnerability in Internet Explorer may be exploited to compromise the  
security of virtual keyboards and virtual keypads. The game may be  
found at