It's a rather interesting name for an exploit kit. Trying to find any references to 'Cotton Castle' you end up with links pointing at an amazing looking location in Turkey - Pamukkale. I can't be sure if the exploit kit name tips you off on the country of the origin, but let's find out what it's made of to be sure we better understand this threat.
more here...........http://malwageddon.blogspot.co.uk/2014/06/cottoncastle-ek-i-hate-to-break-this-to.html
more here...........http://malwageddon.blogspot.co.uk/2014/06/cottoncastle-ek-i-hate-to-break-this-to.html