Unaccepted Third-Party Cookies as the/a Leading Indicator of CNAME Trackers

CNAME-based trackers can allow advertisers to avoid cookie blocking restrictions and potentially introduce security risks. They are currently best detected via exploding and expanding all subdomain calls on a site and comparing against lists of known trackers. While that method works, it also impacts loading times. This research explores if the presence of third-party tracking cookies placed immediately on a user's browser without user consent are a helpful indicator that CNAME trackers are more likely in use, and if they offer a means to a more performant method of CNAME tracker blocking.