Jim Walter, Director of Advanced Threat Research for Intel Security, with contributions from Yuriy Bulygin and John Loucaides, wrote a blog for Dark Reading that summarizes some recent firmware attacks.

Vulnerable From Below: Attacking Hypervisors Using Firmware And Hardware
Malicious attacks with firmware privileges can compromise an entire system, so it is especially important to apply measures to reduce the risks.

Read the full article here:

http://www.darkreading.com/partner-perspectives/intel/vulnerable-from-below-attacking-hypervisors-using-firmware-and-hardware/a/d-id/1321834