"A new form of attack that installs a rootkit directly onto a computer’s BIOS system would render antivirus software useless researchers have warned. Alfredo Ortego and Anibal Sacco of Core Security Technologies explained that the attack was possible against almost all types of commonly used BIOS systems in use today.
The two devised a 100 line Python script that could be flashed onto the BIOS to install a rootkit. Because the BIOS software activated before any other program on a computer when it starts up then normal antivirus software would be unable to detect it. " – Content courtesy of New BIOS attack renders antivirus useless – Security – iTnews Australia