Bypassing EMET 4.1

Bypassing EMET 4.1

The goal of this study is to gauge how difficult it is to bypass the protections offered by EMET, a popular Microsoft zero-day prevention capability. We initially focused on just the ROP protections, but later expanded the study to include a real world example. We were able to bypass EMET’s protections in example code and with a real world browser exploit. The primary novel elements in our research are: 1.Deep study regarding the ROP protections, using example applications to show how to bypass each of the five ROP checks in a generic manner. 2.Detailed real world example showing how to defeat all relevant protections. Look for a new technique to bypass the stack pivot protection, shellcode complete with an EAF bypass, and more. These bypasses leverage generic limitations, and not easily repaired. The impact of this study shows that technologies that operate on the same plane of execution as potentially malicious code, offer little lasting protection. This is true of EMET and other similar userland protections.

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