Mandatory Integrity Control - Application

Application

While processes inherit the integrity level of the process that spawned it, the integrity level can be customized at the time of process creation. As well as for defining the boundary for window messages in the User Interface Privilege Isolation technology, Mandatory Integrity Control is used by applications like Windows Explorer, Internet Explorer, Google Chrome and Adobe Reader to isolate documents from vulnerable objects in the system.

Internet Explorer 7 introduces a MIC-based "Protected Mode" setting to control whether a web page is opened as a low-integrity process or not (provided the operating system supports MIC), based on security zone settings, thereby preventing some classes of security vulnerabilities. Since Internet Explorer in this case runs as a Low IL process, it cannot modify system level objects—file and registry operations are instead virtualized. Adobe Reader 10 and Google Chrome are two other notable applications that are introducing the technology in order to reduce their vulnerability to malware.

However, in some cases a higher IL process do need to execute certain functions against the lower IL process, or a lower IL process need to access resources that only a higher IL process can access (for example, when viewing a webpage in protected mode, save a file downloaded from the internet to a folder specified by the user). High IL and Low IL processes can still communicate with each other by using files, Named pipes, LPC or other shared objects. The shared object must have an integrity level as low as the Low IL process and should be shared by both the Low IL and High IL processes. Since MIC does not prevent a Low IL process from sharing objects with a higher IL process, it can trigger flaws in the higher IL process and have it work on behalf of the low IL process, thereby causing a Squatting attack. Shatter attacks, however, can be prevented by using User Interface Privilege Isolation which takes advantage of MIC.