Anti DLL Injection

Código:

#include   DWORD g_dwLoadLibraryAJMP;  /* HOOK FUNCTION */  DWORD WINAPI jumphook( DWORD AddressToPerformJump, DWORD AddressOfMyFunction, DWORD LenghOfTheAreaToPerformTheJump ) {  if( LenghOfTheAreaToPerformTheJump < 5 )   return 0;   DWORD RelativeJump,      NextInstructionAddress,     Flag;   if ( ! VirtualProtect((LPVOID)AddressToPerformJump, LenghOfTheAreaToPerformTheJump, PAGE_EXECUTE_READWRITE, &Flag) )   return 0;   NextInstructionAddress = AddressToPerformJump + LenghOfTheAreaToPerformTheJump;   *(BYTE*)AddressToPerformJump = 0xE9;   for( DWORD i = 5; i < LenghOfTheAreaToPerformTheJump; i++)   *(BYTE*)(AddressToPerformJump+i) = 0x90;   RelativeJump = AddressOfMyFunction - AddressToPerformJump - 0x5;   *(DWORD*)(AddressToPerformJump + 0x1) = RelativeJump;   VirtualProtect((LPVOID)AddressToPerformJump, LenghOfTheAreaToPerformTheJump, Flag, &Flag);   return NextInstructionAddress;  }  /* END HOOK FUNCTION */  HMODULE WINAPI hLoadLibraryA( LPCSTR lpLibFileName ) {   __asm  {   mov eax, dword ptr ss:[esp + 0x18]   cmp dword ptr ds:[eax-0x12], 0x8B55FF8B   je erro  }     if( lpLibFileName )  {   if( !strcmp( lpLibFileName, "twain_32.dll" ) )    __asm jmp g_dwLoadLibraryAJMP  }      return LoadLibraryExA( lpLibFileName, 0, 0 );  erro:   /* dll injetada */    ExitProcess( 0 );   return 0; }  void ZPerformHooks() {  g_dwLoadLibraryAJMP = (DWORD)GetModuleHandle( "kernel32" ) + 0x6E2A1;   jumphook( (DWORD)LoadLibraryA, (DWORD)&hLoadLibraryA, 57 ); }

Creditos : Allan