The Windows 8 Secure Boot mechanism can be bypassed on PCs from certain manufacturers because of oversights in how those vendors implemented the Unified Extensible Firmware Interface (UEFI) specification, according to a team of security researchers.
The researchers Andrew Furtak, Oleksandr Bazhaniuk and Yuriy Bulygin demonstrated Wednesday at the Black Hat USA security conference in Las Vegas two attacks that bypassed Secure Boot in order to install a UEFI bootkit—boot rootkit—on affected computers.
Source
A Guy