Or you simply can have a database of all websites' SSL certificates[0] and compare it to the website you are accessing or in this case, compare it to the websit

Or you simply can have a database of all websites' SSL certificates[0] and compare it to the website you are accessing or in this case, compare it to the website that buys ad placement. [0] https://www.cloudflare.com/learning/ssl/what-is-an-ssl-certificate/ https://www.cloudflare.com/learning/ssl/what-is-an-ssl-certi...