There is a site that does an auto-check of your system's vulnerability ... that is without ICQ up and running.
http://members.tripod.com/~Revealist
I run ICQ in "Authorized only mode, and Invisible" I too, have been "hacked" and it is too much stress and wasted time to put things to rights again [over and over].
There is another program which alerts to unathorized port access and finds trojans and virus related things.
Will have to find it and post later. I thought I knew where it was. It is neither Norton nor McAfee.
One of the neatest things to put on your machine, if you use it a lot, is MS's Power Toy! Very useful app. Download from Microsoft.