以Kernel32.dll 中的 ReadFile 方法为例:
首先找到 kernel32!ReadFile 函数,从如下截取的汇编代码中可以看到,改函数会调用kernel32!_imp__NtReadFile指向的函数
kernel32!ReadFile+0xd2:
7c801962 bb03010000 mov ebx,103h
7c801967 891e mov dword ptr [esi],ebx
7c801969 8b4608 mov eax,dword ptr [esi+8]
7c80196c 8945d0 mov dword ptr [ebp-30h],eax
7c80196f 8b460c mov eax,dword ptr [esi+0Ch]
7c801972 8945d4 mov dword ptr [ebp-2Ch],eax
7c801975 8b4610 mov eax,dword ptr [esi+10h]
7c801978 6a00 push 0
7c80197a 8d4dd0 lea ecx,[ebp-30h]
7c80197d 51 push ecx
7c80197e ff7510 push dword ptr [ebp+10h]
7c801981 ff750c push dword ptr [ebp+0Ch]
7c801984 56 push esi
7c801985 8bc8 mov ecx,eax
7c801987 80e101 and cl,1
7c80198a f6d9 neg cl
7c80198c 1bc9 sbb ecx,ecx
7c80198e f7d1