The
Novarg / W32/Mydoom.A virus scans the addressbook and local files of the infected machine for email addresses to send the virus copy to. Also, the 'from' address is spoofed.
Generally people don't know how to determine the real source of the virus email (from headers) and send complaints/reports to wrong addresses.
http://spam.abuse.net/userhelp/ has some information how to determine the real source of the email (yes the page is about spam, but determining the real email source is the same for spam and virus emails).
