ActiveX or OLE Custom Control (.ocx)
.ocx file signature | application/octet-stream
DOS MZ executableand its descendants (includingNEandPE)
Magic Bytes
Offset 0
4D 5A
Sources: Wikipedia, Gary Kessler
Extension
.ocx
MIME Type
application/octet-stream
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .ocx files in Python
def is_ocx(file_path: str) -> bool:
"""Check if file is a valid OCX by magic bytes."""
signature = bytes([0x4D, 0x5A])
with open(file_path, "rb") as f:
return f.read(2) == signatureHow to validate .ocx files in Node.js
function isOCX(buffer: Buffer): boolean {
const signature = Buffer.from([0x4D, 0x5A]);
return buffer.subarray(0, 2).equals(signature);
}How to validate .ocx files in Go
func IsOCX(data []byte) bool {
signature := []byte{0x4D, 0x5A}
if len(data) < 2 {
return false
}
return bytes.Equal(data[:2], signature)
}API Endpoint
/api/v1/ocx
curl https://filesignature.org/api/v1/ocx
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .ocx file?
A .ocx file is a ActiveX or OLE Custom Control file. DOS MZ executableand its descendants (includingNEandPE)
What are the magic bytes for .ocx files?
The magic bytes for ActiveX or OLE Custom Control files are 4D 5A at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .ocx file?
To validate a .ocx file, read the first bytes of the file and compare them against the known magic bytes (4D 5A) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .ocx files?
There is no officially registered MIME type for .ocx files. Systems typically use application/octet-stream as a generic fallback when handling this format.
Is it safe to open .ocx files?
ActiveX or OLE Custom Control (.ocx) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.