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Drumlin Fully Secure PDF file (.drmx)

.drmx file signature | application/octet-stream

Drumlin Fully Secure PDF (DRMX) is a proprietary document format developed and maintained by Drumlin Security for protected PDF distribution. It is used for publishing manuals, reports, training materials, and other documents that require controlled access on desktop and mobile readers. Access typically depends on authorization provided by the publisher, so files may not open in standard PDF software; the format remains in use as a rights-management container.

Safe

Magic Bytes

Offset 0
7B 44 52 4D 50 44 4B 7D

Sources: Gary Kessler

Extension

.drmx

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .drmx files in Python

Python 
def is_drmx(file_path: str) -> bool:
    """Check if file is a valid DRMX by magic bytes."""
    signature = bytes([0x7B, 0x44, 0x52, 0x4D, 0x50, 0x44, 0x4B, 0x7D])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .drmx files in Node.js

Node.js 
function isDRMX(buffer: Buffer): boolean {
  const signature = Buffer.from([0x7B, 0x44, 0x52, 0x4D, 0x50, 0x44, 0x4B, 0x7D]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .drmx files in Go

Go 
func IsDRMX(data []byte) bool {
    signature := []byte{0x7B, 0x44, 0x52, 0x4D, 0x50, 0x44, 0x4B, 0x7D}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

GET /api/v1/drmx
curl https://filesignature.org/api/v1/drmx

See the full API documentation for all endpoints and parameters.

Related Formats

.drmz

Frequently Asked Questions

What is a .drmx file?

A .drmx file is a Drumlin Fully Secure PDF file file. Drumlin Fully Secure PDF (DRMX) is a proprietary document format developed and maintained by Drumlin Security for protected PDF distribution. It is used for publishing manuals, reports, training materials, and other documents that require controlled access on desktop and mobile readers. Access typically depends on authorization provided by the publisher, so files may not open in standard PDF software; the format remains in use as a rights-management container.

What are the magic bytes for .drmx files?

The magic bytes for Drumlin Fully Secure PDF file files are 7B 44 52 4D 50 44 4B 7D at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .drmx file?

To validate a .drmx file, read the first bytes of the file and compare them against the known magic bytes (7B 44 52 4D 50 44 4B 7D) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .drmx files?

There is no officially registered MIME type for .drmx files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .drmx files?

Drumlin Fully Secure PDF file (.drmx) 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.