It isn't the first time we see this kind of virus distributions. Sometimes
it is hard to catch such virus when the creator has encrypted his pages.

Our advise is:
keep your virus definitions up-to-date and also the file extensions the
scanner will looking for (running your scanner on all files can decrease
the performance of clients dramatically).
in extreme situations you can install also another scanner on your client.

Also the latest virus software contains new capabilities
f.e.
- verify all in- and outgoing mail,
- verify all downloads,
- verify iexplorer pages
(new facility of latest Norton Antivirus 2002 Professional edition which is an
upgrade of earlier 2002 edition),
- automatically download new definition and configuration files.
greetings.

btw: of course patches are important. mostly isn't a big problem for big
organizations because security is a part of company policy. (very) small
organizations must trust the quality of their virus scanner, which will/must
be always up-to-date.