Using EasyHook to monitor apis which the program called.
EasyHook has four levels. From the bottom up, there are asm level, unmanaged code level, managed code level and your application level.
#How does EasyHook work?
####Note:
1.指令边界问题；
API指令开头被覆盖的指令长度至少是5个字节，需要知道开头被覆盖的指令是占用多少个字节，从而计算下一条指令的地址。
2.被覆盖指令的重定位问题；
hook->oldProc存放被覆盖的指令，其中的call/jmp指令需要重新定位。
tag: Hooking、dll injection