Visibility makes evasion more difficult by increasing the range of analyzable events , de- difficult by increasing the range of analyzable events , de- creasing the risk of having an incorrect view of system creasing the risk of having an incorrect view of system state, and reducing the number of unmonitored avenues state, and reducing the number of unmonitored avenues of attack.
We must also contend with the issue of exploitable bugs in the OS, a serious problem in our world exploitable bugs in the OS, a serious problem in our world of complex operating systems written in unsafe languages, of complex operating systems written in unsafe languages, where new buffer overflows are discovered with disturb- where new buffer overflows are discovered with disturb- ing frequency.
This interface is composed of two parts: first, a Unix domain socket that allows the VMI IDS to send a Unix domain socket that allows the VMI IDS to send commands to, and receive responses and event notifica- commands to, and receive responses and event notifica- tions from, the VMM; and second, a memory-mapped file tions from, the VMM; and second, a memory-mapped file that supports efficient access to the physical memory of that supports efficient access to the physical memory of the monitored VM.
The lie detector module works by directly inspecting The lie detector module works by directly inspecting hardware and kernel state, and by querying the host sys- hardware and kernel state, and by querying the host sys- tem through user-level programs (e.g. ps, ifconfig, tem through user-level programs (e.g. ps, ifconfig, netstat) via a remote shell.
6.2 Event Driven Policy Modules 6.2 Event Driven Policy Modules Event-driven checkers run when the VMM detects Event-driven checkers run when the VMM detects changes to hardware state, such as a write to a sensitive changes to hardware state, such as a write to a sensitive location in memory.