Well excuse me for being a IE 8 feed the hungry user!
Internet Explorer 8 - Better Browser
It sounds like another effort at seeing another botnet for information collection on things like the recent paypal fiascle. For those still using OE, WM, or Outlook the first thing to do with "strange" email with a file attached is dump it right away.
Treat it like the spam you often have to clean out from an ISP email account while a few online clients including WLM block spam in general. With one online provider used here even the genuine MS newletters tend to get flagged with images blocked despite being on the safe sender list!
Even with the new ISP I have to clean out the spam on any account setup through them.

Fortunately that doesn't see the same volume the old one saw and continues to see when I go to look after any lengthy period!

"select all, delete all"!