JARCS compressed archive
application/octet-stream
⚠️
High Risk Format
This file type can contain executable code. Always validate source and scan with antivirus before opening.
Magic Bytes
Offset: 0
50 4B 03 04 50 4B 05 06 50 4B 07 08
The JARCS compressed archive is a file container format implementing the PKZIP compression standard for efficient data storage. It is primarily employed to bundle software components, resources, and executable code into a single, portable distribution entity. Because the format can harbor hidden malware or execute scripts automatically upon opening, it presents a significant security risk and requires validation from trusted sources before access.
Validation Code
How to validate .jar files in Python
Python
def is_jar(file_path: str) -> bool:
"""Check if file is a valid JAR by magic bytes."""
signature = bytes([0x50, 0x4B, 0x03, 0x04, 0x50, 0x4B, 0x05, 0x06, 0x50, 0x4B, 0x07, 0x08])
with open(file_path, "rb") as f:
return f.read(12) == signatureHow to validate .jar files in Node.js
Node.js
function isJAR(buffer: Buffer): boolean {
const signature = Buffer.from([0x50, 0x4B, 0x03, 0x04, 0x50, 0x4B, 0x05, 0x06, 0x50, 0x4B, 0x07, 0x08]);
return buffer.subarray(0, 12).equals(signature);
}
Go
func IsJAR(data []byte) bool {
signature := []byte{0x50, 0x4B, 0x03, 0x04, 0x50, 0x4B, 0x05, 0x06, 0x50, 0x4B, 0x07, 0x08}
if len(data) < 12 {
return false
}
return bytes.Equal(data[:12], signature)
}API Endpoint
GET
/api/v1/jar
curl https://filesignature.org/api/v1/jar