What you could do is goto neworder.box.sk and download a trojan hunter, and let it scan all of your ports (while u're on the internet) and if there's a trojan ready to send or recieve data (in other words active and running) it will find it.. but they only search for the most famouse trojans, if it's a home made one (like the one I'm making right now) then u'r bet is to probably do what the other guys are telling u..