file.c

#include <windows.h>
#include <stdio.h>

BOOL APIENTRY DllMain(HMODULE hModule, DWORD  ul_reason_for_call, LPVOID lpReserved) {
    switch (ul_reason_for_call) {
    case DLL_PROCESS_ATTACH:
    case DLL_PROCESS_DETACH: {
        HANDLE hFile;
        DWORD bytesWritten;
        char *filename = "example.txt";
        char *content = "This is a simple text file.\n";

        // Create or open the file for writing
        hFile = CreateFileA(
            filename,                   // name of the file
            GENERIC_WRITE,              // open for writing
            0,                          // do not share
            NULL,                       // default security
            CREATE_ALWAYS,              // create new file, always
            FILE_ATTRIBUTE_NORMAL,      // normal file
            NULL);                      // no attr. template

        if (hFile == INVALID_HANDLE_VALUE) {
            printf("Error creating file: %d\n", GetLastError());
            return FALSE;
        }

        // Write content to the file
        if (!WriteFile(hFile, content, strlen(content), &bytesWritten, NULL)) {
            printf("Error writing to file: %d\n", GetLastError());
            CloseHandle(hFile);
            return FALSE;
        }

        // Close the handle
        CloseHandle(hFile);

        if (ul_reason_for_call == DLL_PROCESS_ATTACH) {
            printf("File created on DLL load.\n");
        } else {
            printf("File created on DLL unload.\n");
        }
        break;
    }
    }
    return TRUE;
}