Windows XP是通过sysenter调用KiFastCallEntry将ntdll.dll的调用切换到内核的。KiFastCallEntry的原理是通过在SSDT中查找函数地址跳转。所以只要伪造一张原始SSDT，就可以使得SSDT-HOOK无效了。-Windows XP by calling KiFastCallEntry sysenter ntdll.dll call will switch to the kernel. KiFastCallEntry SSDT principle i

Check ring0 vulnerability in Windows kernels. Checked: 1. SYSENTER 2. IO Write Memory 3. Bus Write Memory 4. Reset CPU in ring0 5. Zero IDT