In this research, we've explored attack surface of hypervisors and TrustZone monitor in modern ARM based phones, using Google Nexus 5X, Nexus 6P, and Pixel as primary targets. We will explain different attack scenarios using SMC and other interfaces, as well as interaction methods between TrustZone and hypervisor privilege levels.
We will explore attack vectors which could allow malicious operating system (EL1) level to escalate privileges to hypervisor (EL2) level and potentially install virtualization rootkit in the hypervisor. We will also explore attack vectors through SMC and other low level interfaces, interactions between TrustZone and hypervisor (EL2) privilege levels. To help with further low level ARM security research, we will release ARM support for CHIPSEC framework and new modules to test issues in ARM based hypervisors and TrustZone implementations, including SMC fuzzer.