Apart from getting in the way and being generally annoying, there's an increasing rate of attachments along with all the joyous security concerns.
Out of every 1000 machines the report suggests that 8.6 are infected with a virus or malware of some kind. Interesting geographical distribution whilst we're at it:
Used in Spam overwhelms e-mail messages on the BBC website. Image originally produced by the lovely, lovely people at Microsoft...
I'd say that suggests to be careful of anything coming out of Russia and Brazil.
All the more reason to do the things which should be standard: decent anti-virus; update regularly; employ service packs; check for malware and spyware. Oh, and just don't open attachments or download stuff from sites without checking them first.
(The report) found that Office document attachments and PDF files were increasingly being targeted by hackers.As I've said before, the number of people who simply don't seem to be aware they have to do this stuff always baffles me. But, you know, keep on downloading and adding friends on msm. Nothing bad can come of that...
From: Spam overwhelms e-mail messages, BBC website