mite be a worm , have you got full up to date anti virus software 2004
and spybot from http://www.download.com and have you adding any MSN plug in s to MSN messager 3 plus.have you got MSN plus? .and if so what site you been to if you use MSN plug ins?. you may have a hacker have you got a firewall too ?.. http://www.zonealarm.com .