IDENTIFIER magic bytes (.identifier)
.identifier file signature: 5B 5A 6F 6E 65 54 72 61 | application/octet-stream
The Microsoft Zone Identifier is an NTFS alternate data stream created and maintained by Microsoft Windows to record the source zone of downloaded files. It is used by Windows and compatible applications to support security prompts, file trust decisions, and attachment handling for items obtained from the internet or other untrusted locations. It is a legacy metadata feature rather than a standalone document format, and its presence can be altered or removed by some tools.
Magic Bytes
Offset 0
5B 5A 6F 6E 65 54 72 61
Sources: Wikipedia
All Known Signatures
2 signature variants are documented for .identifier files across multiple sources.
Validation Code
How to validate .identifier files in Python
def is_identifier(file_path: str) -> bool:
"""Check if file is a valid IDENTIFIER by magic bytes."""
signature = bytes([0x5B, 0x5A, 0x6F, 0x6E, 0x65, 0x54, 0x72, 0x61])
with open(file_path, "rb") as f:
return f.read(8) == signatureHow to validate .identifier files in Node.js
function isIDENTIFIER(buffer: Buffer): boolean {
const signature = Buffer.from([0x5B, 0x5A, 0x6F, 0x6E, 0x65, 0x54, 0x72, 0x61]);
return buffer.subarray(0, 8).equals(signature);
}How to validate .identifier files in Go
func IsIDENTIFIER(data []byte) bool {
signature := []byte{0x5B, 0x5A, 0x6F, 0x6E, 0x65, 0x54, 0x72, 0x61}
if len(data) < 8 {
return false
}
return bytes.Equal(data[:8], signature)
}API Endpoint
/api/v1/identifier
curl https://filesignature.org/api/v1/identifier
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .identifier file?
A .identifier file is identified by the magic bytes 5B 5A 6F 6E 65 54 72 61 at byte offset 0. The Microsoft Zone Identifier is an NTFS alternate data stream created and maintained by Microsoft Windows to record the source zone of downloaded files. It is used by Windows and compatible applications to support security prompts, file trust decisions, and attachment handling for items obtained from the internet or other untrusted locations. It is a legacy metadata feature rather than a standalone document format, and its presence can be altered or removed by some tools.
What are the magic bytes for .identifier files?
The magic bytes for IDENTIFIER (.identifier) files are 5B 5A 6F 6E 65 54 72 61 at byte offset 0. These bytes identify the file format more reliably than the extension alone.
How do I validate a .identifier file?
To validate a .identifier file, read the first bytes of the file and compare them against the known magic bytes (5B 5A 6F 6E 65 54 72 61) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .identifier files?
There is no officially registered MIME type for .identifier files. Systems typically use application/octet-stream as a generic fallback when handling this format.
Is it safe to open .identifier files?
IDENTIFIER (.identifier) 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.