This is a mass mailing virus which really took off last Monday.  It is the fastest spreading virus ever created.  As many such attacks go, it spoofs itself as coming from an address that is not the source.  This one is especially convincing and trys to trick you into opening the attachment.  I have been receiving over 300 of these each day with no let up in sight.  It has taken down several email servers temporarily and slowed web sites and mail delivery world wide.

Virus software has tagged this one since Monday evening, but be extra cautious of any email with an attachment and make certain it is legit before opening.  Many of them will appear to be from someone you trust.  I even got several dozen from myself   :'(

It goes by other names too.  For complete details:

http://securityresponse.symantec.com/avcenter/venc/data/w32.novarg.a@mm.html