Nokia phone backup file (.nbu)

.nbu file signature | application/octet-stream

The NBU (Nokia phone backup) format is a proprietary backup file format developed by Nokia for its mobile devices. It was used by Nokia PC Suite and related software to store contacts, messages, calendar data, settings, and other handset content for restoration or migration. The format is largely legacy, reflecting older Nokia platforms, and backup files are generally safe but should still be obtained from trusted sources before opening.

Safe

Magic Bytes

Offset 0


              CC 52 33 FC E9 2C 18 48 AF E3 36 30 1A 39 40 06

Sources: Gary Kessler

Extension

.nbu

MIME Type

application/octet-stream

Byte Offset

Risk Level

Safe

Validation Code

How to validate .nbu files in Python

Python

def is_nbu(file_path: str) -> bool:
    """Check if file is a valid NBU by magic bytes."""
    signature = bytes([0xCC, 0x52, 0x33, 0xFC, 0xE9, 0x2C, 0x18, 0x48, 0xAF, 0xE3, 0x36, 0x30, 0x1A, 0x39, 0x40, 0x06])
    with open(file_path, "rb") as f:
        return f.read(16) == signature

How to validate .nbu files in Node.js

Node.js

function isNBU(buffer: Buffer): boolean {
  const signature = Buffer.from([0xCC, 0x52, 0x33, 0xFC, 0xE9, 0x2C, 0x18, 0x48, 0xAF, 0xE3, 0x36, 0x30, 0x1A, 0x39, 0x40, 0x06]);
  return buffer.subarray(0, 16).equals(signature);
}

How to validate .nbu files in Go

func IsNBU(data []byte) bool {
    signature := []byte{0xCC, 0x52, 0x33, 0xFC, 0xE9, 0x2C, 0x18, 0x48, 0xAF, 0xE3, 0x36, 0x30, 0x1A, 0x39, 0x40, 0x06}
    if len(data) < 16 {
        return false
    }
    return bytes.Equal(data[:16], signature)
}

API Endpoint

GET /api/v1/nbu


              curl https://filesignature.org/api/v1/nbu

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .nbu file?

A .nbu file is a Nokia phone backup file file. The NBU (Nokia phone backup) format is a proprietary backup file format developed by Nokia for its mobile devices. It was used by Nokia PC Suite and related software to store contacts, messages, calendar data, settings, and other handset content for restoration or migration. The format is largely legacy, reflecting older Nokia platforms, and backup files are generally safe but should still be obtained from trusted sources before opening.

What are the magic bytes for .nbu files?

The magic bytes for Nokia phone backup file files are CC 52 33 FC E9 2C 18 48 AF E3 36 30 1A 39 40 06 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .nbu file?

To validate a .nbu file, read the first bytes of the file and compare them against the known magic bytes (CC 52 33 FC E9 2C 18 48 AF E3 36 30 1A 39 40 06) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .nbu files?

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

Is it safe to open .nbu files?

Nokia phone backup file (.nbu) 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.