* Some email viruses spreading WITHOUT opening attachment
Systems running Internet Explorer (IE) version 5.0 and/or MS 
Office 2000 are vulnerable to some virus attacks using most 
email systems, even if the email recipient opens no attachments.  

You don't even have to use IE; just have it installed with the 
default security settings.  If you have not closed the hole, 
you can receive viruses (and spread them) by viewing or 
previewing malicious email without opening any attachment, or 
by visiting a malicious web site. The problem is caused by a 
programming bug in an Internet Explorer ActiveX control called
scriptlet.typelib.  

This is by far the fastest growing virus distribution problem 
and ripe for a hugely destructive event - at least as large as 
the ILOVEYOU virus.  Updating your virus detection software,
while important, is not an effective solution for this problem. 
You must also close the hole.  The hole can be closed in five 
minutes or less using tools available at Microsoft's security site:
http://www.microsoft.com/security/bulletins/ms99-032.asp 
The correction script may be run directly from:
http://www.microsoft.com/msdownload/iebuild/scriptlet/en/scriptlet.htm