ISZ
application/octet-stream
Magic Bytes
Offset: 0
49 73 5A 21
The Zipped ISO Disk Image (ISZ) is a proprietary compressed disk image format developed by EZB Systems for use with their UltraISO software. This format allows users to compress standard ISO disc images to reduce storage requirements while retaining the ability to mount the image directly. It supports Advanced Encryption Standard (AES) encryption and file spanning, though it requires specific third-party tools for mounting or extraction on most operating systems.
Validation Code
How to validate .isz files in Python
Python
def is_isz(file_path: str) -> bool:
"""Check if file is a valid ISZ by magic bytes."""
signature = bytes([0x49, 0x73, 0x5A, 0x21])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .isz files in Node.js
Node.js
function isISZ(buffer: Buffer): boolean {
const signature = Buffer.from([0x49, 0x73, 0x5A, 0x21]);
return buffer.subarray(0, 4).equals(signature);
}
Go
func IsISZ(data []byte) bool {
signature := []byte{0x49, 0x73, 0x5A, 0x21}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
GET
/api/v1/isz
curl https://filesignature.org/api/v1/isz