Description:

Binwalk is a tool for searching a given binary image for embedded
files and executable code. Specifically, it is designed for
identifying files and code embedded inside of firmware images. Binwalk
uses the libmagic library, so it is compatible with magic signatures
created for the Unix file utility.

Binwalk also includes a custom magic signature file which contains
improved signatures for files that are commonly found in firmware
images such as compressed/archived files, firmware headers, Linux
kernels, bootloaders, filesystems, etc.