Stealthy Deployment and Execution of In-Guest Kernel Agents
As more and more Virtual Machines (VM) are packed into a physical machine, refactoring common kernel components shared by virtual machines running on the same physical machine could significantly reduce the overall resource consumption. The refactored kernel component typically runs on a special VM called a virtual appliance. Because of the semantics gap in Hardware Abstraction Layer (HAL)-based virtualization, a physical machine's virtual appliance requires the support of per-VM inguest agents to perform VM-specific operations such as kernel data structure access and modification. To simplify deployment, these agents must be injected into guest virtual machines without requiring any manual installation. Moreover, it is essential to protect the integrity of in-guest agents at run time, especially when the underlying refactored kernel service is security-related.