We present FRAK**, the firmware reverse analysis konsole. FRAK is a framework for unpacking, analyzing, modifying and repacking the firmware images of proprietary embedded devices. The FRAK framework provides a programmatic environment for the analysis of arbitrary embedded device firmware as well as an interactive environment for the disassembly, manipulation and re-assembly of such binary images. We demonstrate the automated analysis of Cisco IOS, Cisco IP phone and HP LaserJet printer firmware images. We show how FRAK can integrate with existing vulnerability analysis tools to automate bug hunting for embedded devices. We also demonstrate how FRAK can be used to inject experimental host-based defenses into proprietary devices like Cisco routers and HP printers.