the connections you found can be blocked by changing these configuration directives:
browser.newtabpage.enabled security.OCSP.enabled browser.safebrowsing.enabled browser.safebrowsing.malware.enabled privacy.trackingprotection.pbmode.enabled browser.search.suggest.enabled browser.search.update extensions.blocklist.enabled extensions.update.enabled extensions.getAddons.cache.enabled datareporting.healthreport.service.enabled toolkit.telemetry.enabled network.http.speculative-parallel-limit and may be: beacon.enabled browser.send_pings from time to time I have collected a list of configuration directives to stop automatic connections to remote hosts you can find at http://www.trek.eu.org/text/firefox-tuning.html I hope this can help