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

Hook KiFastCallEntry

SSDT HOOK,学习inline hook等相关的技术原理，非常值得参考。-Technical principles related SSDT HOOK, learning inline hook so very worth considering.