Security Fail, Windows 7: File Extensions still concealed
The release candidate for Windows 7 is now available for download. Finnish anti-virus firm F-Secure, have observed 
that Microsoft persists in deceiving users on the true nature of file types, by hiding file extensions of known file types in Windows 7.
The default behavior of Windows Explorer in every version of Windows from Windows 2000 through Windows Vista is to represent files using icons, and to hide each file’s extension type, such as “.txt” for text files, “.doc” for Microsoft Word files, and so on.
That means that our average Windows user opens up their “My Documents” folder, doesn’t see the “.doc” extensions that accompany Microsoft Word files, or the “.pdf”. They just see a bunch of programs represented by tiny icons.
Let’s just say, that there is a virus writer out there, and the computer worm he wants to spam out to the rest of world is called nice.exe. If he renames that program to “nice.txt.exe”, the file will appear to Windows recipients who have not changed the default settings as “nice.txt”.
While fiddling with a file type in Windows can change the appearance of the icon that represents the file in Windows Explorer, attackers also can change the icon inside the executable to look like the icon of a text file or an image, and everybody would be fooled, as F-Secure notes.
