Virus found in the message

Scanner: MailMonitor for SMTP v1.2.2 

Problem description:
Email data:
MessageID: [off-list ref]
From: <redacted>
To: <redacted>
Cc: 
Subject: Re: Movie
Scanning part []

Scanning part [your_details.zi]
Attachment validity check: passed.
Virus identity found: W32/Sobig-E






-------------------------------------------------------
This SF.Net email sponsored by: Free pre-built ASP.NET sites including
Data Reports, E-commerce, Portals, and Forums are available now.
Download today and enter to win an XBOX or Visual Studio .NET.
http://aspnet.click-url.com/go/psa00100006ave/direct;at.asp_061203_01/01