A hoax circulating since February 2008 warns users to beware of "the worst virus ever" in the form of an email attachment titled "POSTCARD" or "POSTCARD FROM HALLMARK." Though real e-card viruses certainly do exist, this one is a hoax.
Note that while some versions of the hoax below claim the information was "verified" on Snopes.com, this is NOT true. What has been verified is a different e-card virus threat with a similar name. Proceed with caution!
Protecting Yourself From Viral Hoaxes and Threats
With so many real viruses in circulation with names almost identical to the bogus threats you may read about in hoax messages like the ones below, it’s crucial to know how to distinguish real virus threats from bogus ones.
http://urbanlegends.about.com/od/fauxphotos/fl/Postcard-from-Hallmark-Virus-Hoax-Urban-Legends.htm