User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.102 Safari/537.36 Vivaldi/1.93.955.38 Steps to reproduce: Downloaded and run firefox installer for windows from getfirefox.com Actual results: see following url in transparent proxy, which means download goes through http 1508705230.582 36999 172.28.30.21 TCP_MISS/200 38701542 GET http://download.cdn.mozilla.net/pub/firefox/releases/56.0.1/win64/en-US/Firefox%20Setup%2056.0.1.exe - ORIGINAL_DST/92.51.99.200 application/x-ms Expected results: download should go through https, not sure if installer is checking integrity and/or signing key of package (if exists), if not - this is a serious issue.