a third party programe.
you must have to downloaded somethings . And inside the installer of the programe there was a spywar.
[link=http://www.lavasoftusa.com/download_and_buy/product_comparison_chart.php]http://www.lavasoftusa.com/download_and_buy/product_comparison_chart.php[/link]
if u don't have it download it and scan ur computer.
If it still doesnt work try to ask him nicely or check any usage of your network with a snifer...
I cant remember the name ...arf...maybe type etherpeek or snif ethe....Ok its :
http://www.ethereal.com/download.html
you snife then u read...and then you know wich programe are actualy using ur connection.
If you need any assistance with that program just let me know.