Suspect email virus infection

I found a file on my desktop this morning that was just labeled
" ~ ". I opened it with notepad & along with a bunch of programming type characters were at least several if not all of my address book contents. Has this happened to anyone else & what can I do about it? I use Zone Alarm & it locks internet access after 10 min of inactivity so I don't know if anything went out or not but I am concerned about spreading malicious emails. Any help will be appreciated. I have run norton AV 2003 with recent definition files & no virus's were detected.

Thanks in advance.

AaronSales