Already seen this a thousand times as well?
Those bast*ds are getting more clever. They put their SPAM messages into
a single GIF and add many buzz words at the bottom. The message arrives
most of the time with different sender and different recipient addresses
make it's hard to define filters for Spamassassin to wipe this crap out.

I didn't find many commonnesses between the messages yet but I have
published a Procmail recipe that works at least:

http://infocopter.com/know-how/procmail/Recipes-WE_HAVE_A_RUNNER.html

You may also check my incoming and out-filtered sender list on this URL:

http://infocopter.com/incoming-virus/virus_watch.log

--reto