Hello, you are using an old browser that's unsafe and no longer supported. Please consider updating your browser to a newer version, or downloading a modern browser.

Global Accelerated Learning • Est. 1999
Glossary Term File Signature

Training Camp • Cybersecurity Glossary

What is File Signature?

A file signature, or magic number, is a byte sequence identifying a file's true format regardless of its extension, used widely in digital forensics.

Glossary > Incident Response & Forensics > File Signature

Understanding File Signature

A file signature, also called a magic number or magic bytes, is a fixed sequence of bytes at a known offset, usually the start of a file, that identifies its format independent of the file extension. Forensic and security tools use these signatures to detect a file's true type, identify mismatched or disguised extensions, and carve files from raw disk images. For example, PNG files begin with the bytes 89 50 4E 47, and PDF files begin with the ASCII string %PDF.

Learn More About File Signature:

Ready to Get Certified?

Turn knowledge into credentials with our instructor-led cybersecurity boot camps.

View All Courses →