There is a virus that inserts the underline character in front of the sender's name. I would definitely not open the attachment, and probably just permanently delete the email. The virus or worm automatically sends itself out to addresses it finds in the infected computer. The user can't be blamed. Check it out at http://www.symantec.com/avcenter or go to your own virus-protection webpage to find out more about it. USUALLY you're not infected unless you open the file attached. Good luck.....