Signs of a scanner include a click within seconds of delivery, several links opened almost at once, requests from the network of a security vendor or a data centre, and requests that do not behave like a real browser. HawkOpen has a named rule for each of these signs.
Every click gets a category, such as security scanner, link preview or human, a confidence of “possible” or “likely”, and the list of rules that matched. A click that comes from a data-centre network is never classified as likely human activity.