ISZ (.isz)
.isz file signature | application/octet-stream
ISZ (ISO Zipped) is a compressed disc image format developed and maintained by EZB Systems, the company behind UltraISO. It is used to store optical disc images in a reduced-size form for software distribution, backups, and mounting in virtual drives. The format is generally safe, though, like other disk images, it should be opened only from trusted sources because it can contain executable content or malicious files.
Magic Bytes
Offset 0
49 73 5A 21
Sources: Wikipedia
Extension
.isz
MIME Type
application/octet-stream
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .isz files in 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
function isISZ(buffer: Buffer): boolean {
const signature = Buffer.from([0x49, 0x73, 0x5A, 0x21]);
return buffer.subarray(0, 4).equals(signature);
}How to validate .isz files in 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
/api/v1/isz
curl https://filesignature.org/api/v1/isz
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .isz file?
A .isz file is identified by the magic bytes 49 73 5A 21 at byte offset 0. ISZ (ISO Zipped) is a compressed disc image format developed and maintained by EZB Systems, the company behind UltraISO. It is used to store optical disc images in a reduced-size form for software distribution, backups, and mounting in virtual drives. The format is generally safe, though, like other disk images, it should be opened only from trusted sources because it can contain executable content or malicious files.
What are the magic bytes for .isz files?
The magic bytes for ISZ files are 49 73 5A 21 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .isz file?
To validate a .isz file, read the first bytes of the file and compare them against the known magic bytes (49 73 5A 21) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .isz files?
There is no officially registered MIME type for .isz files. Systems typically use application/octet-stream as a generic fallback when handling this format.
Is it safe to open .isz files?
ISZ (.isz) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.