Is there a way with htaccess rules to stop the download of a specific zip file unless its been linked through the site. Ie. Stop people from copy and pasting of link or pasting link onto address bar or another site.
Something similar to regular hotlink protection should work:
Essentially, specify your domain, and if the referrer doesn't match it will return a 403 - forbidden page instead of the file.
Be careful with referrers though, as they may not always be set.