[Mimedefang] patch to add blocking of encrypted email via uv scan

[David F. Skoll]

On Tue, 9 Dec 2003 WBrown at e1b.org wrote:

> It would slow the virus from propagating though, because it would have to
> encrypt each version sent separately.

Encryption could be a problem.  It is possible to write a polymorphic
virus that has essentially no "signature".  That is, it's possible to
write a virus that mutates itself such that two different mutations
have no pattern in common longer than a couple of bytes (and that's
too short to trigger on without heaps of false-positives.)

I'm somewhat surprised we haven't seen a virus kit that does this, but
we probably will within the next few years.

Regards,

David.