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EnCase case file (.cas)

.cas file signature | application/octet-stream

EnCase case file (and backup)

Safe

Magic Bytes

Offset 0
5F 43 41 53 45 5F

Sources: Gary Kessler

Extension

.cas

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .cas files in Python

Python 
def is_cas(file_path: str) -> bool:
    """Check if file is a valid CAS by magic bytes."""
    signature = bytes([0x5F, 0x43, 0x41, 0x53, 0x45, 0x5F])
    with open(file_path, "rb") as f:
        return f.read(6) == signature

How to validate .cas files in Node.js

Node.js 
function isCAS(buffer: Buffer): boolean {
  const signature = Buffer.from([0x5F, 0x43, 0x41, 0x53, 0x45, 0x5F]);
  return buffer.subarray(0, 6).equals(signature);
}

How to validate .cas files in Go

Go 
func IsCAS(data []byte) bool {
    signature := []byte{0x5F, 0x43, 0x41, 0x53, 0x45, 0x5F}
    if len(data) < 6 {
        return false
    }
    return bytes.Equal(data[:6], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .cas file?

A .cas file is a EnCase case file file. EnCase case file (and backup)

What are the magic bytes for .cas files?

The magic bytes for EnCase case file files are 5F 43 41 53 45 5F at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .cas file?

To validate a .cas file, read the first bytes of the file and compare them against the known magic bytes (5F 43 41 53 45 5F) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .cas files?

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

Is it safe to open .cas files?

EnCase case file (.cas) 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.