Some have indicated that this code is malicious in the form of malware or spyware. I am not certain if that is true or not. However, here is the path that it takes to mature into the error message I originally documented in the question.
First, adzerk is loaded in the Stack Overflow page through a script tag in the <div id="sidebar">. Indeed all of this action takes place in the sidebar.
<script>
var ados = ados || {};ados.run = ados.run || [];
ados.run.push(function() {
ados_add_placement(22,8277,"adzerk1716529536",17).setZone(45) ;
});
</script>
Once ados is present, it then produces an iframe and a div, among a few other things. The iframe is what is in question though.
<div class="everyonelovesstackoverflow adzerk-vote" id="adzerk1716529536">
<iframe id="ados_frame_adzerk1716529536_81029" frameborder="0" scrolling="no" height="250" width="220">
This iframe then contains a set of nested iframes. This is where the malicious (or accidental) scripting takes place. The first item inside of the "ados_frame" iframe is this:
<script>
new function() {
this.rand = Math.floor((Math.random() + "") * 1000000000000);
this.dvparams = 'ctx=1842468&cmp=1844697&plc=451838910&sid=451838910';
this.dvregion = '0';
this.tagsrc = '<iframe src="http://view.atdmt.com/CNT/iview/451838910/direct/01?click=" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" topmargin="0" leftmargin="0" allowtransparency="true" width="220" height="250">\
<scr'+'ipt language="Javascr'+'ipt" type="text/javascr'+'ipt">\
document.write(\'<a href="http://clk.atdmt.com/CNT/go/451838910/direct/01/" target="_blank"><img src="http://view.atdmt.com/CNT/view/451838910/direct/01/"/></a>\');\
</scr'+'ipt></iframe>';
this.altsrc = '<style>\
.container {\
border: 1px solid #3b599e;\
overflow: hidden;\
filter: progid:DXImageTransform.Microsoft.gradient(startColorstr=\'#315d8c\', endColorstr=\'#84aace\'); /* For Internet Explorer */\
background: -webkit-gradient(linear, left top, left bottom, from(#315d8c), to(#84aace)); /* For WebKit browsers */\
background: -moz-linear-gradient(top, #315d8c, #84aace); /* For Firefox 3.6+ */ \
}\
.cloud {\
color: #fff;\
position: relative;\
font: 100% "Times New Roman", Times, serif;\
text-shadow: 0px 0px 10px #fff;\
line-height: 0;\
}\
</style>\
<scr'+'ipt type="text/javascr'+'ipt">\
function cloud(){\
var b1 = "<div class=\\"cloud\\" style=\\"font-size: ";\
var b2 = "px; position: absolute; top: ";\
document.write(b1+"300px; width: 300px; height: 300"+b2+"34px; left: 28px;\\">.<\\/div>");\
document.write(b1+"300px; width: 300px; height: 300"+b2+"46px; left: 10px;\\">.<\\/div>");\
document.write(b1+"300px; width: 300px; height: 300"+b2+"46px; left: 50px;\\">.<\\/div>");\
document.write(b1+"400px; width: 400px; height: 400"+b2+"24px; left: 20px;\\">.<\\/div>");\
}\
function clouds(){\
var top = [\'-80\',\'80\',\'240\',\'400\'];\
var left = -10;\
var a1 = "<div style=\\"position: relative; top: ";\
var a2 = "px; left: ";\
var a3 = "px;\\"><scr'+'ipt type=\\"text/javascr'+'ipt\\">cloud();<\\/scr'+'ipt><\\/div>";\
for(i=0; i<8; i++)\
{\
document.write(a1+top[0]+a2+left+a3);\
document.write(a1+top[1]+a2+left+a3);\
document.write(a1+top[2]+a2+left+a3);\
document.write(a1+top[3]+a2+left+a3); \
if(i==4)\
{\
left = -90;\
top = [\'0\',\'160\',\'320\',\'480\'];\
}\
else left += 160;\
}\
}\
</scr'+'ipt>\
<div class="container" style="width: 220px; height: 250px;">\
<scr'+'ipt type="text/javascr'+'ipt">clouds();</scr'+'ipt>\
</div>';
this.callbackName = '__dvredirect_callback_' + this.rand;
var thisRedirect = this;
window[this.callbackName] = function () { return thisRedirect; };
var src = 'http://rtbcdn.doubleverify.com/bsredirect5.js?callback=' + this.callbackName;
document.write('<scr' + 'ipt src=' + src + '></scr' + 'ipt>');
}
</script>
It starts to go downhill from here, as a host of scripts are loaded. Inside of that block you can see the call to doubleverify. You can see a call to atdmt. And what isn't initially obvious is the nested calls which exist in the next iframe. A slough of scripts are loaded after this. For example:
<script type="text/javascript" src="http://c.betrad.com/surly.js#;ad_w=300;ad_h=250;coid=343;nid=11908;check_container=true;ecaid=451838910;"></script>
However, my main point lies above.
this.tagsrc = '<iframe src="http://view.atdmt.com/CNT/iview/451838910/direct/01?click="...
Is a line of code loaded by the sidebar through adzerk. This frame then continues on a very questionable path leading to the errors noted in the question.
Out of curiosity, I followed the links which were trying to force redirection. It led me to here
http://www.windowsazure.com/en-us/solutions/mobile/?WT.mc_id=AzureBG_US_Display_StackOverflow_Q3_GrSP_MobileV2D_MobServ
And a genuine offer for a free trial of Windows Azure. I understand some people may not trust Microsoft, but I would doubt they would place anything malicious in their ads and have not seen any negative affects of the errors or visiting the link.
@Jan - Please see the answer listed below. This is not on my machine. It is generated by inline html on the stackoverflow page itself.