V7#3 of Woody’s Windows Watch offers some very good insight into Secunia’s Internet Explorer File Download Extension Spoofing advisory. None of the information in the Woody’s Watch article is really new but it explains things in ways that helps one (me, in particular) understand the exposures a little better.
(If that link to the Woody’s Watch article doesn’t work yet, try this one and if it still doesn’t work, try again in a few hours — I just got the email newsletter and there’s sometimes a lag before the newsletter makes it on to his website.)
The long and short of Woody’s article: NEVER use “Open” when you’re downloading a file, ALWAYS use “Save”, even if you think you’re an expert on these things. And if you’re reading email and there’s an attachment, even if it looks benign (“no, that’s not an executable, it’s a PDF”), it might not be — check to make sure that the sender actually sent you the email and included the attachment. And, again, don’t “Open” the attachment, “Save” it and make sure it’s what you think it is.