Dynamically terminating the Steam WebHelper.

README.md

Example of the program running: https://www.youtube.com/watch?v=3famXyrOGEs
Make sure to have Steam already running in the background.

DynamicSteamWebHelperSuspension.c

#include <windows.h>
#define printf __builtin_printf

BOOL EnumWindowsProc(HWND hWnd, LPARAM lParam)
{
    DWORD maxCount = GetWindowTextLengthW(hWnd) + 1;
    WCHAR className[256] = {}, windowText[maxCount] = {};
    GetClassNameW(hWnd, className, 256);
    GetWindowTextW(hWnd, windowText, maxCount);
    if (!wcscmp(L"vguiPopupWindow", className))
        //   while (!IsWindowVisible(hWnd))
        ShowWindow(hWnd, SW_HIDE);
    //  return FALSE;
    return TRUE;
}

INT WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, INT nShowCmd)
{

    HKEY keyHandle = NULL, subKeyHandle = NULL;
    HANDLE eventHandle = CreateEventW(NULL, TRUE, FALSE, NULL),
           threadHandle = OpenThread(THREAD_SUSPEND_RESUME, FALSE, GetWindowThreadProcessId(FindWindowW(L"vguiPopupWindow", L"Untitled"), NULL));
    WCHAR keyName[255] = {}, runningAppName[255] = {};
    HWND windowHandle = NULL;
    BOOL appRunning = FALSE;
    DWORD i = 0, dataSize = 0;
    //
    //  printf("%ld\n", threadHandle);
    RegOpenKeyExW(HKEY_CURRENT_USER, L"SOFTWARE\\Valve\\Steam\\Apps", 0, KEY_ALL_ACCESS, &keyHandle);
    while (TRUE)
    {
        RegNotifyChangeKeyValue(keyHandle, TRUE, REG_NOTIFY_CHANGE_LAST_SET, eventHandle, TRUE);
        WaitForSingleObject(eventHandle, INFINITE);
        while (!RegEnumKeyExW(keyHandle, i, keyName, &((DWORD){255}), NULL, NULL, NULL, NULL))
        {
            RegOpenKeyExW(keyHandle, keyName, 0, KEY_ALL_ACCESS, &subKeyHandle);
            RegGetValueW(subKeyHandle, NULL, L"Name", RRF_RT_REG_SZ, NULL, NULL, &dataSize);
            WCHAR *appName = _malloca(dataSize);
            if (dataSize)
            {
                RegGetValueW(subKeyHandle, NULL, L"Name", RRF_RT_REG_SZ, NULL, appName, &dataSize);
                RegGetValueW(subKeyHandle, NULL, L"Running", RRF_RT_REG_DWORD, NULL, &appRunning, &((DWORD){sizeof(BOOL)}));
                if (appRunning && !wcslen(runningAppName))
                {

                    printf("%ld\n", windowHandle);
                    EnumWindows(EnumWindowsProc, 0);
                    SuspendThread(threadHandle);
                    printf("%ls | %ls | %ld\n", keyName, appName, appRunning);
                    system("taskkill /f /im steamwebhelper.exe");
                    wcscpy(runningAppName, appName);
                }
                else if (!appRunning && !wcscmp(runningAppName, appName))
                {
                    memset(runningAppName, 0, sizeof(runningAppName));
                    printf("%ls | %ls | %ld\n", keyName, appName, appRunning);
                    ResumeThread(threadHandle);
                }
            }
            RegCloseKey(subKeyHandle);
            i += 1;
        }
        i = 0;
    }
    RegCloseKey(keyHandle);
    return EXIT_SUCCESS;
}