New Mass Mailing Virus
An infected email may have a subject of: Test, Hi, Hello, Mail Delivery System, Mail Transaction Failed, Server Report, Status, or Error. The file attachment (22,528 bytes in size) may use a variety of names and name extensions (pif, scr, exe, cmd, bat, zip). You are encouraged to delete any email you receive with the above characteristics.
Please also be aware that this virus forges the From: line on randomly chosen email messages residing on infected computers. For this reason, you may receive a notification stating that you have sent an infected email message. If you receive such a notification and you have recently updated your anti-virus package, it is most likely that your email address was on an infected machine. Your computer probably is not infected.
Major antivirus vendors have released new updates to identify and remove infected attachments. Please update your anti-virus programs to protect your computers.
Additional references:
http://securityresponse.symantec.com/avcenter/venc/data/w32.novarg.a@mm.html#threatassessment
http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=WORM_MIMAIL.R