.HTA File Extension

Program that can be run from an HTML document; an executable file that contains hypertext code; can be created by simply changing the file extension of a .HTM file to a ".HTA" extension; run by the Microsoft HTML Application Host (Mshta.exe).

When an HTA file is accessed on the Web, it typically produces a dialog box that says: "What would you like to do with this file?"
[ ] Run this program from its current location
[ ] Save this program to disk