MMM
application/octet-stream
Magic Bytes
Offset: 0
52 49 46 46 52 4D 4D 50
The Microsoft Multimedia Movie (MMM) is a legacy container format developed by Microsoft for storing simple animations and video sequences within the Resource Interchange File Format (RIFF) structure. It was primarily used during the Windows 3.x era to embed short video clips, screensavers, and basic animations into early multimedia applications. Considered obsolete today and replaced by modern containers like AVI, this format is rarely encountered and poses minimal security risk due to its lack of active scripting capabilities.
Validation Code
How to validate .mmm files in Python
Python
def is_mmm(file_path: str) -> bool:
"""Check if file is a valid MMM by magic bytes."""
signature = bytes([0x52, 0x49, 0x46, 0x46, 0x52, 0x4D, 0x4D, 0x50])
with open(file_path, "rb") as f:
return f.read(8) == signatureHow to validate .mmm files in Node.js
Node.js
function isMMM(buffer: Buffer): boolean {
const signature = Buffer.from([0x52, 0x49, 0x46, 0x46, 0x52, 0x4D, 0x4D, 0x50]);
return buffer.subarray(0, 8).equals(signature);
}
Go
func IsMMM(data []byte) bool {
signature := []byte{0x52, 0x49, 0x46, 0x46, 0x52, 0x4D, 0x4D, 0x50}
if len(data) < 8 {
return false
}
return bytes.Equal(data[:8], signature)
}API Endpoint
GET
/api/v1/mmm
curl https://filesignature.org/api/v1/mmm