You got an email attachment with an DOC/PPT/XLS etc. extension but when you open it via Microsoft Office you get an cryptic output and the first line of that document tells you this:
(This file must be converted with BinHex 4.0)
It’s a BIN file send by a Mac OS X user (mostly) but the extension is set wrong (intentional or accidently!?!?).
So what now?
You can decode that BIN file via these two tools:
Decode Shell Extension <- My favorite