Which tool is used to reconstruct firmware images for embedded devices?

• A. Binwalk
• B. Firmware Mod Kit
• C. Telnet
• D. Nmap

Answer: (B)

Reconstructing firmware images for embedded devices requires unpacking the original image, making changes, and repacking a new image that can be flashed back to the device. The Firmware Mod Kit is designed for this workflow: it provides scripts and utilities to unpack firmware images, modify the filesystem or binaries inside, and then reassemble them into a new, flashable firmware. It streamlines the process of handling different firmware formats and helps you repack the modified contents into a usable image.

Binwalk is great for analyzing and extracting components from a firmware image, but it doesn’t automatically repackage a modified image into a deployable firmware. The other options—Telnet and Nmap—are unrelated to reconstructing firmware images.