Maven Mapper's

A new virus that disguises itself as Internet Explorer 7 Beta 2 is just making its way across the Internet.  The virus comes into your inbox in the form of an e-mail with just a simple link.  There is no executable file in the e-mail.  The e-mail appears to come from Microsoft and clicking the link takes you to a website where you are encouraged to click a button to install a beta version of IE 7 Beta2. 

Bad install actually includes a virus known as Win32.Grum.  Security experts still don't know exactly what the virus does and they warned that many major vendors are not picking up the virus. 

Detection of Win32.Grum by anti-virus programs was "mediocre" by last evening, according to Sunbelt Software, and some big vendors were still not picking it up Friday morning, Hypponen said.

Source: Techworld.com - Users offered virus disguised as IE7

So unless you hear about a beta offering a Microsoft project from Microsoft's website itself, you should ignore it and probably delete it.