The actual ITSF file is embedded in what appears to be an invalid executable file (not sure if MSDOS or PE)
It is an .its section
The exe also has a .rsrc section with a version resource

There seems to be a CAOL block before the ITSF initial header

Initial header:

char[4] ITSF
DWORD 4 (version number)
DWORD 32
DWORD 1
QWORD 9176
DWORD timestamp
DWORD LCID
{Header Section 0 integrated into initial header
DWORD 0x01fe (unknown)
DWORD 0 (unknown)
QWORD ITSF File Size
DWORD 0 (unknown)
DWORD 0 (unknown)
}
GUID
GUID

Directory ?:

IFCM Header: 32 bytes
AOLL Chunk: 512 bytes

IFCM Header: 32 bytes
AOLL Chunk: 8224 bytes
	contains same directory entries as in ITSF 2 & 3

Content section 0

Namelist file is the same

The format of the .its section is exactly the same as the .LIT format used by the MSReader ebook software, except without encryption & different internal files.
See the source code of a program called open convert lit for more info on the ITSF 4 format (+ .lit internal files)
It is availble at http://www.kyz.uklinux.net/convlit.php3
