The Dink Network

Most probably someone else then WC has been infected but that worm uses the adressbook and spoofs the "from" part. (Example: You could recieve a mail from Tal but actually it came from Kyle)

lol that makes the mystery a little bigger.

Also it would help those certain users to tell them which Virus you recieved from them. (and lookup the info about the virus)

Greetz,
Shampoo173