Email Virus

This morning I got a rather strange email from my friend Stacie, which of course turns out to be some sort of virus. I didn't open the attachment but somehow it was still activated. Sent out a warning to everyone in my address book, don't open anything with an attachment! However, I think I have infected the entire bombay expats yahoo group - everyone hates me.

That said, the virus doesn't seem to be do much except send out random emails with attachment, most of them easily identifiable. I don't really know anything about viruses - What should I do? (please post comments)