Lexmark Printers Firmware Extraction - Part C

This blog post documents a technical firmware reverse-engineering effort on a Lexmark MS811 printer: the author downloads an FLS update, locates and analyzes PJL handlers in on-device binaries, identifies embedded RSA public keys and AES usage, describes the encrypted section/header format and decryption workflow, and successfully extracts the kernel and filesystem images. The writeup explains the file format, key-loading logic, and extraction results for analysts, and does not describe an active compromise or exploit in the wild.