Spammers adapt (zip spam)

Less than a month ago spammers started to send spam using PDF files. SARE reacted immediately providing PDFInfo ruleset for SpamAssassin. Thanks to them, ruleset was very effective. My current setup is almost spam free due to combining of several spam-fighting techniques. But I was getting so much of this PDF spam and was so happy to get rid of it with new SARE rules.

Now spammers adapted. They send attachments az pseudo-zip files (in fact, rar files), which are not caught by any filters. Fortunately I found that ClamAV can catch [almost] all...