Guardian: Hypervisor as Security Foothold for Personal Computers

Abstract. Personal computers lack of a security foothold to allow the end-users to protect their systems or to mitigate the damage. Existing candidates either rely on a large Trusted Computing Base (TCB) or are too costly to widely deploy for commodity use. To fill this gap, we propose a hypervisor-based security foothold, named as Guardian, for commodity personal computers. We innovate a bootup and shutdown mechanism to achieve both integrity and availability of Guardian. We also propose two security utilities based on Guardian. One is a device mon-itor which detects malicious manipulation on camera and network adaptors. The other is hyper-firewall whereby Guardian expects incoming and outgoing network packets based on policies specified by the user. We have implemented Guardian ( ≈ 25K SLOC) and the two utilities ( ≈ 2.1K SLOC) on a PC with an Intel pro-cessor. Our experiments show that Guardian is practical and incurs insignificant overhead to the system.