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InstallShield Script (.ins)

.ins file signature | application/octet-stream

InstallShield Script (INS) is a script-based installer format created by InstallShield and currently maintained by Flexera for use with its setup-authoring tools. It is used to define installation logic, file deployment, registry changes, and other actions in Windows software installation packages. The format is generally safe, but it is associated with legacy installer workflows and should be opened only from trusted software vendors.

Safe

Magic Bytes

Offset 0
B8 C9 0C 00

Sources: Gary Kessler

Extension

.ins

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .ins files in Python

Python 
def is_ins(file_path: str) -> bool:
    """Check if file is a valid INS by magic bytes."""
    signature = bytes([0xB8, 0xC9, 0x0C, 0x00])
    with open(file_path, "rb") as f:
        return f.read(4) == signature

How to validate .ins files in Node.js

Node.js 
function isINS(buffer: Buffer): boolean {
  const signature = Buffer.from([0xB8, 0xC9, 0x0C, 0x00]);
  return buffer.subarray(0, 4).equals(signature);
}

How to validate .ins files in Go

Go 
func IsINS(data []byte) bool {
    signature := []byte{0xB8, 0xC9, 0x0C, 0x00}
    if len(data) < 4 {
        return false
    }
    return bytes.Equal(data[:4], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .ins file?

A .ins file is a InstallShield Script file. InstallShield Script (INS) is a script-based installer format created by InstallShield and currently maintained by Flexera for use with its setup-authoring tools. It is used to define installation logic, file deployment, registry changes, and other actions in Windows software installation packages. The format is generally safe, but it is associated with legacy installer workflows and should be opened only from trusted software vendors.

What are the magic bytes for .ins files?

The magic bytes for InstallShield Script files are B8 C9 0C 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .ins file?

To validate a .ins file, read the first bytes of the file and compare them against the known magic bytes (B8 C9 0C 00) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .ins files?

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

Is it safe to open .ins files?

InstallShield Script (.ins) 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.