The best anti virus software

For some time now, Google Calendar users have been vulnerable to a rather nasty type of spam that seems to have gained momentum lately. It works like this: an email containing an invitation to an event is sent by a spammer to your Google Calendar (this can apparently happen even with an email that ends up in your spam folder), and the calendar automatically puts the appointment into your calendar — even though the body of the appointment contains a spam link or some other obnoxious content.