Microsoft security catalog file
application/octet-stream
Magic Bytes
Offset: 0
30 00 00 00 4C 66 4C 65
The Microsoft security catalog file is a digital signature container format developed and maintained by Microsoft for verifying the integrity of software components. These files store cryptographic hashes for groups of files and are primarily used to validate device drivers, Windows system updates, and third-party software installations. By centralizing signatures, the format allows the operating system to confirm that associated files remain untampered with since their original distribution by an authorized vendor.
Validation Code
How to validate .cat files in Python
Python
def is_cat(file_path: str) -> bool:
"""Check if file is a valid CAT by magic bytes."""
signature = bytes([0x30, 0x00, 0x00, 0x00, 0x4C, 0x66, 0x4C, 0x65])
with open(file_path, "rb") as f:
return f.read(8) == signatureHow to validate .cat files in Node.js
Node.js
function isCAT(buffer: Buffer): boolean {
const signature = Buffer.from([0x30, 0x00, 0x00, 0x00, 0x4C, 0x66, 0x4C, 0x65]);
return buffer.subarray(0, 8).equals(signature);
}
Go
func IsCAT(data []byte) bool {
signature := []byte{0x30, 0x00, 0x00, 0x00, 0x4C, 0x66, 0x4C, 0x65}
if len(data) < 8 {
return false
}
return bytes.Equal(data[:8], signature)
}API Endpoint
GET
/api/v1/cat
curl https://filesignature.org/api/v1/cat