1. A method, comprising: building a steganographic extractor to extract hidden information contained in binary images; loading the steganographic extractor during a pre-boot phase of a computer system; discovering, during the pre-boot phase, binary firmware images on which a steganographic operation has been performed to generate hidden information contained within each binary firmware image; and extracting, via the steganographic extractor during the pre-boot phase, the hidden information contained in each binary firmware image that is discovered.