UltraISO

UltraISO is a crippleware application for Microsoft Windows for creating, modifying and converting ISO image files used for optical disc authoring, currently being produced by EZB Systems.

UltraISO
A screenshot of UltraISO
Developer(s)	EZB Systems
Initial release	April 20, 2002
Stable release	9.76.3860 / 8 July 2023; 2 years ago (2023-07-08)[1]
Operating system	Microsoft Windows
Platform	IA-32 and x86-64
Type	Optical disc authoring software and virtual drive
License	Commercial
Website	www.ezbsystems.com/ultraiso/

Initially UltraISO was shareware however since 2006 it has turned into commercial software.^[2] The 'Free Trial' version is limited to ISO images of 300 MB or less, effectively making it Crippleware.^[3]

ISZ format

UltraISO uses a proprietary format known as ISZ. The format is advertised as "ISO Zipped", even though it is not a simple zip archive. The format uses zlib or bzip2 to compress the data, and may use AES-128,192 or 256 encryption in the CBC mode^[4] (note that this provides no integrity protection and is vulnerable to the padding oracle attack^[5]). The file format specification is available publicly on EZB Systems's website.^[4] The format is now supported by third-party applications such as Daemon Tools, Alcohol 120%, CDemu and isz-tool.

See also

• List of optical disc authoring software
• Live USB
• Comparison of ISO image software