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Outlook Express address book (.wab)

.wab file signature | application/octet-stream

Outlook Express address book (Win95)

Safe

Magic Bytes

Offset 0
81 32 84 C1 85 05 D0 11 B2 90 00 AA 00 3C F6 76

Sources: Gary Kessler

All Known Signatures

2 signature variants are documented for .wab files across multiple sources.

Hex Signature Offset Sources
81 32 84 C1 85 05 D0 11 B2 90 00 AA 00 3C F6 76 0 Gary Kessler
9C CB CB 8D 13 75 D2 11 91 58 00 C0 4F 79 56 A4 0 Gary Kessler

Extension

.wab

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .wab files in Python

Python 
def is_wab(file_path: str) -> bool:
    """Check if file is a valid WAB by magic bytes."""
    signature = bytes([0x81, 0x32, 0x84, 0xC1, 0x85, 0x05, 0xD0, 0x11, 0xB2, 0x90, 0x00, 0xAA, 0x00, 0x3C, 0xF6, 0x76])
    with open(file_path, "rb") as f:
        return f.read(16) == signature

How to validate .wab files in Node.js

Node.js 
function isWAB(buffer: Buffer): boolean {
  const signature = Buffer.from([0x81, 0x32, 0x84, 0xC1, 0x85, 0x05, 0xD0, 0x11, 0xB2, 0x90, 0x00, 0xAA, 0x00, 0x3C, 0xF6, 0x76]);
  return buffer.subarray(0, 16).equals(signature);
}

How to validate .wab files in Go

Go 
func IsWAB(data []byte) bool {
    signature := []byte{0x81, 0x32, 0x84, 0xC1, 0x85, 0x05, 0xD0, 0x11, 0xB2, 0x90, 0x00, 0xAA, 0x00, 0x3C, 0xF6, 0x76}
    if len(data) < 16 {
        return false
    }
    return bytes.Equal(data[:16], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .wab file?

A .wab file is a Outlook Express address book file. Outlook Express address book (Win95)

What are the magic bytes for .wab files?

The magic bytes for Outlook Express address book files are 81 32 84 C1 85 05 D0 11 B2 90 00 AA 00 3C F6 76 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .wab file?

To validate a .wab file, read the first bytes of the file and compare them against the known magic bytes (81 32 84 C1 85 05 D0 11 B2 90 00 AA 00 3C F6 76) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .wab files?

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

Is it safe to open .wab files?

Outlook Express address book (.wab) 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.