Windows/DOS executable file (.com)
.com file signature | application/x-msdownload
Windows/DOS executable file(SeeThe MZ EXE File Formatpage for the structure of an EXE file,with coverage of NE, TLINK, PE, self-extracting archives, and more.)Note:MZ are the initals of Mark Zbikowski, designer of the DOS executable file format.
High Risk Format
This file type can contain executable code. Always validate the source and scan with antivirus before opening.
Magic Bytes
Offset 0
4D 5A
Sources: Apache Tika, Gary Kessler
Extension
.com
MIME Type
application/x-msdownload
Byte Offset
0
Risk Level
High
Validation Code
How to validate .com files in Python
def is_com(file_path: str) -> bool:
"""Check if file is a valid COM by magic bytes."""
signature = bytes([0x4D, 0x5A])
with open(file_path, "rb") as f:
return f.read(2) == signatureHow to validate .com files in Node.js
function isCOM(buffer: Buffer): boolean {
const signature = Buffer.from([0x4D, 0x5A]);
return buffer.subarray(0, 2).equals(signature);
}How to validate .com files in Go
func IsCOM(data []byte) bool {
signature := []byte{0x4D, 0x5A}
if len(data) < 2 {
return false
}
return bytes.Equal(data[:2], signature)
}API Endpoint
/api/v1/com
curl https://filesignature.org/api/v1/com
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .com file?
A .com file is a Windows/DOS executable file file. Windows/DOS executable file(SeeThe MZ EXE File Formatpage for the structure of an EXE file,with coverage of NE, TLINK, PE, self-extracting archives, and more.)Note:MZ are the initals of Mark Zbikowski, designer of the DOS executable file format.
What are the magic bytes for .com files?
The magic bytes for Windows/DOS executable file 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 .com file?
To validate a .com 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 .com files?
The primary MIME type for .com files is application/x-msdownload.
Is it safe to open .com files?
Windows/DOS executable file (.com) files are high risk because they can contain executable code. Never open .com files from untrusted sources. Always scan with antivirus software, verify the source, and consider running in a sandboxed environment.