* Windows defines the file type by the letters after the last period; i.e., DIAMONDINV.TXT.vbs
* Lower case extensions can make you miss the real extension. Look!
* The icon should match the file type you are expecting.
* Watch for the ellipses to indicate padded spaces to hide the real extension. DIAMOND.TXT ... Extensions to be very wary of:
EXE, COM, BAT: Native executables
VBS, VBE: Visual Basic Scripts
HTA: HTML Application
REG: Registry Files
SHS: Scrap Objects
DOC,XL, XLS, XLA: Office files that might contain Macros
CSLID: Refers to registered controls
A searchSecurity user sent in this comment on Rick's tip:
In regards to Executable e-mail attachments -- Educate the end user, I would only add that it is important to make sure Windows is NOT set to hide file extensions for known file types! Otherwise, there's a good chance you won't read the file extension.