Microsoft Fax Cover Sheet
application/octet-stream
Magic Bytes
Offset: 0
46 44 42 48 00
Microsoft Fax Cover Sheet (CPE) is a proprietary file format developed and maintained by Microsoft Corporation for its Windows Fax and Scan utility. These files function as templates that define the visual layout, text fields, and graphical logos displayed on the initial page of transmitted fax documents. Although this legacy format remains integrated into modern Windows versions, it is considered safe and primarily serves users maintaining traditional telecommunication workflows.
Validation Code
How to validate .cpe files in Python
Python
def is_cpe(file_path: str) -> bool:
"""Check if file is a valid CPE by magic bytes."""
signature = bytes([0x46, 0x44, 0x42, 0x48, 0x00])
with open(file_path, "rb") as f:
return f.read(5) == signatureHow to validate .cpe files in Node.js
Node.js
function isCPE(buffer: Buffer): boolean {
const signature = Buffer.from([0x46, 0x44, 0x42, 0x48, 0x00]);
return buffer.subarray(0, 5).equals(signature);
}
Go
func IsCPE(data []byte) bool {
signature := []byte{0x46, 0x44, 0x42, 0x48, 0x00}
if len(data) < 5 {
return false
}
return bytes.Equal(data[:5], signature)
}API Endpoint
GET
/api/v1/cpe
curl https://filesignature.org/api/v1/cpe