I've always used the EICAR test virus
(http://www.eicar.org/anti_virus_test_file.htm) to verify the operation of
my virus scanning software, but somehow never became aware of the services
that will e-mail you a test virus for the same purpose. Although there are
several of these services, this one will send you a variety of formats (your
choice), and doesn't require any signup or verification of your e-mail
address. I've been testing ZIP file scanning, and that's one of the choices
they offer. http://www.declude.com/Articles.asp?ID=99
If you're not familiar with the EICAR test virus, check it out at the first
link.