The file being pushed, free.exe, is an installerfor Antivirus XP 2008, a nasty rogue antispyware program.
As we all know, for quite some time now, spam has stopped just being a nuisance, and became a serious potential security threat. It used to be that one wouldn’t get too upset if the occasional Viagra email got through a spam filter. That’s no longer the case: Spam is a significant vector for malware infection through malicious links and social engineering, and if something gets through a spam filter — and then makes it past endpoint protection — one can have all kinds of nasty headaches.
Alex Eckelberry
(thanks Adam)