02.Basic Concept for a Windows Application

In order to hack a Windows application using Python, it is necessary to have basic knowledge of the Windows API. Windows API consists of a set of Application Programming Interfaces (APIs) provided by Microsoft. In order to develop an application using Windows API, it is necessary to use various functions that are supported by the operating system (Kernel). For a commonly used 32-bit Windows environment, the Windows API called Win32 API is supported.

Figure 2-1 Python Using External Libraries

We use libraries like “lib” and “DLL” when a windows application is developed. “Lib” is a static library that it is included when a Windows executable file is created. “DLL” (Dynamically linked libraries) provides a dynamic library that is called during the execution time of the application. We can use the most of the Win32 API in the form of the DLL, where typically the following DLLs are used.

Type	Characteristics
kernel32.dll	Provides the ability to access basic resources, such as threads, file system, devices, processes
user32.dll	Provides the ability to change the user interface, including creating and managing windows, receiving window messages, displaying text on the screen, and presenting a message box
advapi32.dll	Provides the ability to modify the registry, shutdown and restart the system, also provides support functions to start / end / generate Windows services, account management
gdi32.dll	Manages functions for the printer, monitor and other output devices
comdlg32.dll	Open a file, save a file, manage the standard dialog window associated with the selected color and font
comctl32.dll	Status bar, progress bar, acces to applications that are supported by the operating system, such as the toolbar
shell32.dll	Provides the functionality of the shell of the operating system so that the applications can have access
netapi32.dll	Provides a variety of communication features that are supported by the operating system to the applications

Table 2-1 Windows DLLs

The development language for Windows (Visual Basic, Visual C ++, such as C #) can be used by calling the Win32 API directly. The Win32 API provides a variety of interfaces that can be used to control the function of the level of the operating system. These are widely used not only to develop applications but also to debug and develop hacking programs.