SISX (.sisx)

.sisx file signature | application/vnd.symbian.install

Symbian Installation System eXtension (SISX) is an application package format created for the Symbian operating system and maintained through the Symbian software distribution ecosystem. It is used to install mobile applications, updates, and optional components on Symbian devices. The format is now legacy, and although generally safe as a package container, files from untrusted sources should be checked before installation.

Safe

Magic Bytes

Offset 8


              19 04 00 10

Sources: Apache Tika tika-mimetypes.xml

Extension

.sisx

MIME Type

application/vnd.symbian.install

Byte Offset

Risk Level

Safe

Validation Code

How to validate .sisx files in Python

Python

def is_sisx(file_path: str) -> bool:
    """Check if file is a valid SISX by magic bytes at offset 8."""
    signature = bytes([0x19, 0x04, 0x00, 0x10])
    with open(file_path, "rb") as f:
        f.seek(8)
        return f.read(4) == signature

How to validate .sisx files in Node.js

Node.js

function isSISX(buffer: Buffer): boolean {
  const signature = Buffer.from([0x19, 0x04, 0x00, 0x10]);
  if (buffer.length < 12) return false;
  return buffer.subarray(8, 12).equals(signature);
}

How to validate .sisx files in Go

func IsSISX(data []byte) bool {
    signature := []byte{0x19, 0x04, 0x00, 0x10}
    if len(data) < 12 {
        return false
    }
    return bytes.Equal(data[8:12], signature)
}

API Endpoint

GET /api/v1/sisx


              curl https://filesignature.org/api/v1/sisx

See the full API documentation for all endpoints and parameters.

Related Formats

.sis

Frequently Asked Questions

What is a .sisx file?

A .sisx file is identified by the magic bytes 19 04 00 10 at byte offset 8. Symbian Installation System eXtension (SISX) is an application package format created for the Symbian operating system and maintained through the Symbian software distribution ecosystem. It is used to install mobile applications, updates, and optional components on Symbian devices. The format is now legacy, and although generally safe as a package container, files from untrusted sources should be checked before installation.

What are the magic bytes for .sisx files?

The magic bytes for SISX files are 19 04 00 10 at byte offset 8. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .sisx file?

To validate a .sisx file, read the first bytes of the file and compare them against the known magic bytes (19 04 00 10) at offset 8. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .sisx files?

The primary MIME type for .sisx files is application/vnd.symbian.install.

Is it safe to open .sisx files?

SISX (.sisx) 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.