base64 encoding/klez?

[ISP List]

>If you'll check it you'll find that it isn't infected.  Klez seems to
>attach a couple of files, and (at least with F-Prot) the infected one is
>cleaned and sent on.
>
>Michael

I don't doubt that it has been cleaned, but the odd thing is that it
appears in the *body* of the message and is not an attachment at all.  It
only happens with Klez it seems.  I don't understand why it isn't being
treated like any other attachment.

--Mike