Backstab | A tool to kill antimalware protected processes

Backstab is a C library. Backstab has no bugs, it has no vulnerabilities and it has medium support. You can download it from GitHub.

Have these local admin credentials but the EDR is standing in the way? Unhooking or direct syscalls are not working against the EDR? Well, why not just kill it? Backstab is a tool capable of killing antimalware protected processes by leveraging sysinternals’ Process Explorer (ProcExp) driver, which is signed by Microsoft. ProcExp has a signed kernel driver that it loads on startup, which allows it to kill handles that cannot be killed even as an administrator. When you use the UI, you cannot kill a protected process, but you can kill it handles because ProcExp UI instructs the kernel driver to kill those handles. Backstab does the same thing but without the UI element. Here is a quick rundown of what happens. While the tool purpose is listing and killing handles, the opportunities are vast. It is possible to duplicate the handles to your own process instead of killing them. This could allow for deeper tampering where you write to files, fire events, hold mutexes. To support further research, I tried to make the code readable and split it to many methods to facilitate reuse, I also left a description on all ProcExp related methods. Feel free to reach out to me on Twitter or by Email.