So far, this new virus is not widespread and it's easy to avoid through best practices. Microsoft never sends updates by email as users must download them from their website. Attachments should never be opened unless you are certain they are safe.

Elitper.A - Pretends to be a patch from Microsoft
http://www.symantec.com/avcenter/venc/data/w32.elitper.a@mm.html
W32.Elitper.A@mm is a mass-mailing worm that spreads using MAPI and through file-sharing networks. It also lowers Windows security settings by altering the Hosts file to prevent access to antivirus-related Web sites.

FORMAT OF EMAIL TO AVOID
From: <spoofed>
Subject: Fwd:None
Message Body: Microsoft(c) Lastest Update For CD-ROM
Attachment: Firewall.exe
Size of attachment: 9,392 bytes