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Addrs + WIP
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0xZ0F committed Mar 17, 2020
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3 changes: 3 additions & 0 deletions Chapter 7 - Windows/7.2 Privileges.md
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Expand Up @@ -9,6 +9,9 @@ To protect critical OS components, data, and processes, there are two privilege
## User-Mode to Kernel-Mode
Sometimes a user-mode process needs to access kernel-mode functionality. This happens very often such as when rendering windows or graphics. When a user-mode process calls a system service, special instructions are executed that switch the thread to kernel-mode. Once the service finishes, the thread is switched back to user-mode.

**User-mode code runs in the memory range of 0x00000000 to 0x7FFFFFFF.**
**Kernel-mode code runs in the memory range of 0x80000000 to 0xFFFFFFFF.**

## Hypervisor
With the boom of virtualization, there was a need for a way to run high-performance OS guests efficiently. To facilitate this virtualization, hypervisors are used. **Hypervisors** allow for the separation and isolation of all system components including virtual memory, physical memory, USB devices, and more. Hypervisors have more privileges and abilities than kernel-mode applications due to their ability to virtualize and isolate components. Because of this, Windows uses the hypervisor for security, this is known as *virtualization-based security* (VBS). Some of the components in VBS are the Hyper Guard, Credential Guard, Application Guard, Host Guardian, Shielded Fabric, and more. I won't explain all of these components, but I will briefly explain two of them.
* **Hyper Guard** - Protects important kernel and hypervisor related data structures and code.
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2 changes: 2 additions & 0 deletions README.md
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# ATTENTION:
## **This course is still in early development. I plan on adding a significant amount of content. For now, this course is going to be hosted here on Github, however, that will most likely change in the future. To stay updated, follow me on [Twitter](https://twitter.com/0xZ0F).**

**Unfortunately, I have become quite busy, so course updates are going to be extremely slow. This course has not been abandoned, I promise.**

This course is a side project, so updates may be slow. The course is free, and it will remain that way, so don't expect me to spend countless hours working on it. Thank you.

## Read [BeforeYouBegin](@BeforeYouBegin.md)
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