This new mass mailing worm is rated as a "2" at Symantec and it will most likely be contained as many sites block PIF based attachments. 
Netsup.A - new mass mailing worm
http://www.symantec.com/avcenter/venc/data/w32.netsup.a@mm.html Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP
W32.Netsup.A@mm can arrive as an attachment to an email with the following properties:
From: NetworkSupport@<RECIPIENT DOMAIN> or spoofed address from an infected Microsoft Outlook address book.
Subjects: May contain one of the following:
Tragedy
Protecting your PC
This pic of you is funny
W32.Netsky and W32.Beagle protection
Finances for the week
Mail Delivery Subsystem Error
Careful
Undeliverable Message
Mail Delivery Failed Name of attachment: message.eml.pif
EXAMPLE: 