[ganselo]

По второму пункту:
На форме TButton (Button1), TMemo (Memo) и TIdHTTP (HTTPQuery)

Код:

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString md5Hesh = "d8578edf8458ce06fbc5bb76a58c5ca4";
    TStringList *post = new TStringList;
    TStringStream *response = new TStringStream("");

    post->Add("chain=" + md5Hesh);

    try
    {
        HTTPQuery->Post("http://www.virustotal.com/search.html", post, response);
    }
    catch(EIdSocketError &se)
    {
        ShowMessage(se.Message);
    }
    catch(Exception &e)
    {
        ShowMessage(e.Message);
    }
    ShowMessage(response->DataString);

    delete HTTPQuery, post, response;

}
//---------------------------------------------------------------------------

void __fastcall TForm1::HTTPQueryRedirect(TObject *Sender,
      AnsiString &dest, int &NumRedirect, bool &Handled,
      AnsiString &VMethod)
{
    Memo->Lines->Add(HTTPQuery->Get(dest));
    Handled = false;
}
//---------------------------------------------------------------------------

А вот как парсить результат не знаю.