[Exim] Klez virus/worm

We're seeing a lot of messages containing what looks like a variant of Klez
(possibly Klez-F?) coming in at the moment.

The messages seem to have a body of type multipart/alternative and one of the
sub-parts is a windows executable with a filename that ends in BAT or EXE (eg).

For some reason these messages have NOT been caught by the current filter.
This may be due to spaces or other special characters (eg []) in the filenames.

Are other sites seeing this, maybe I missed the discussion?
Steve