Install Shield v5
application/vnd.ms-cab-compressed
Magic Bytes
Offset: 0
4D 53 43 46
Microsoft Cabinet (CAB) is a proprietary compressed archive format developed by Microsoft for software distribution and system component storage. It is primarily utilized by the Windows Installer, Windows Update services, and third-party setup tools like InstallShield to package drivers and installation files for efficient deployment. Originally optimized for multi-disk distribution, the format remains a core element of the Windows operating system for managing internal file integrity and compression.
Validation Code
How to validate .cab files in Python
Python
def is_cab(file_path: str) -> bool:
"""Check if file is a valid CAB by magic bytes."""
signature = bytes([0x4D, 0x53, 0x43, 0x46])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .cab files in Node.js
Node.js
function isCAB(buffer: Buffer): boolean {
const signature = Buffer.from([0x4D, 0x53, 0x43, 0x46]);
return buffer.subarray(0, 4).equals(signature);
}
Go
func IsCAB(data []byte) bool {
signature := []byte{0x4D, 0x53, 0x43, 0x46}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
GET
/api/v1/cab
curl https://filesignature.org/api/v1/cab