I have just discovered that someone has been using my email address to send out spam to contacts in my Outlook 2003 contact list.
I am currently running a ZoneAlarm Anti-Virus/Spyware Ultra-deep scan.

I also have HijackThis, although i am not sure what I should be looking for in its log.
Other than that... Can anyone please give me some suggestions and strategies for eliminating this problem?

Thanks in advance for any assistance!

Operating System:Windows Vista Ultimate
Software Version:8.0
Product Name:ZoneAlarm Internet Security Suite