Introducing Ring -3 Rootkits: a BIOS rootkit targeting vPro chipsets (2009) [scribd] (blackhat.com)
http://media.ccc.de/browse/congress/2013/30C3_-_5380_-_en_-_saal_2_-_201312291830_-_persistent_stealthy_remote-controlled_dedicated_hardware_malware_-_patrick_stewin.html