Outlook Express address book
application/octet-stream
Magic Bytes
Offset: 0
81 CD AB
The Outlook Express address book (WAB) is a proprietary file format developed by Microsoft for storing contact information within its early email clients. It serves as the primary database for Outlook Express and earlier versions of Windows, organizing names, email addresses, and phone numbers for user communication. As a legacy format replaced by modern contact management systems in Windows Vista and later, it remains structurally safe but is largely obsolete for current productivity workflows.
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, 0xCD, 0xAB])
with open(file_path, "rb") as f:
return f.read(3) == signatureHow to validate .wab files in Node.js
Node.js
function isWAB(buffer: Buffer): boolean {
const signature = Buffer.from([0x81, 0xCD, 0xAB]);
return buffer.subarray(0, 3).equals(signature);
}
Go
func IsWAB(data []byte) bool {
signature := []byte{0x81, 0xCD, 0xAB}
if len(data) < 3 {
return false
}
return bytes.Equal(data[:3], signature)
}API Endpoint
GET
/api/v1/wab
curl https://filesignature.org/api/v1/wab