From the doc: 'Stub is 15KB packed, 27KB unpacked! Stub coded using pure low-level Win32 API, to give a lightning fast command interpretor and file extractor. Up to 50 commands can be configured! Compatible with Windows 9x/NT/ME/2K/XP. (Untested on 95, NT and ME) Output file can have the extension '.exe', '.bat', '.com', '.pif', or '.scr'. Easy to use Windows-style GUI, featuring shortcut keys, helpful error messages, and shell drag-n-drop! Very simple (and weak) encryption algorithm to mask files and data from anti-virus detection. The stub used for the final file can be either a UPX pre-compressed stub (15KB), or the uncompressed (27KB) stub, which can be compressed with a exe-packer of your choice. The icon of the output file can be changed. (Using icons built into YAB, or import your own icons.) Stub can melt itself after execution. The settings can be saved, along with the currently selected icon, and loaded at a later time for re-use. The order of execution of the commands can be changed at any time before the final file is built.'