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Windows MSinfo file (.mof)

.mof file signature | application/octet-stream

Windows MSinfo file (MOF) is a Microsoft file format used by Windows and maintained by Microsoft for storing system information and configuration data. It is primarily used by the System Information utility and related administrative tools to export hardware, software, and troubleshooting details. The format is generally safe and text-based, but older .mof files may reflect legacy Windows diagnostics and should be reviewed before sharing due to contained system details.

Safe

Magic Bytes

Offset 0
FF FE 23 00 6C 00 69 00 6E 00 65 00 20 00 31 00

Sources: Gary Kessler

Extension

.mof

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .mof files in Python

Python 
def is_mof(file_path: str) -> bool:
    """Check if file is a valid MOF by magic bytes."""
    signature = bytes([0xFF, 0xFE, 0x23, 0x00, 0x6C, 0x00, 0x69, 0x00, 0x6E, 0x00, 0x65, 0x00, 0x20, 0x00, 0x31, 0x00])
    with open(file_path, "rb") as f:
        return f.read(16) == signature

How to validate .mof files in Node.js

Node.js 
function isMOF(buffer: Buffer): boolean {
  const signature = Buffer.from([0xFF, 0xFE, 0x23, 0x00, 0x6C, 0x00, 0x69, 0x00, 0x6E, 0x00, 0x65, 0x00, 0x20, 0x00, 0x31, 0x00]);
  return buffer.subarray(0, 16).equals(signature);
}

How to validate .mof files in Go

Go 
func IsMOF(data []byte) bool {
    signature := []byte{0xFF, 0xFE, 0x23, 0x00, 0x6C, 0x00, 0x69, 0x00, 0x6E, 0x00, 0x65, 0x00, 0x20, 0x00, 0x31, 0x00}
    if len(data) < 16 {
        return false
    }
    return bytes.Equal(data[:16], signature)
}

API Endpoint

GET /api/v1/mof
curl https://filesignature.org/api/v1/mof

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .mof file?

A .mof file is a Windows MSinfo file file. Windows MSinfo file (MOF) is a Microsoft file format used by Windows and maintained by Microsoft for storing system information and configuration data. It is primarily used by the System Information utility and related administrative tools to export hardware, software, and troubleshooting details. The format is generally safe and text-based, but older .mof files may reflect legacy Windows diagnostics and should be reviewed before sharing due to contained system details.

What are the magic bytes for .mof files?

The magic bytes for Windows MSinfo file files are FF FE 23 00 6C 00 69 00 6E 00 65 00 20 00 31 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .mof file?

To validate a .mof file, read the first bytes of the file and compare them against the known magic bytes (FF FE 23 00 6C 00 69 00 6E 00 65 00 20 00 31 00) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .mof files?

There is no officially registered MIME type for .mof files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .mof files?

Windows MSinfo file (.mof) 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.