there is a known issue where scammers setup Look-Alike Domains so the URL appears like apple.com or your bank to deceive unsuspecting users ... see https://hackaday.com/2017/04/19/you-think-you-cant-be-phished/ I tested this on ff nightly and the Look-Alike hacked site just appeared as https://www.аррӏе.com/ ff has setting in about:config network.IDN_show_punycode which defaults to false ... when set to true above issue is resolved and browser properly shows actual underlying faked URL as https://www.xn--80ak6aa92e.com/ and not https://www.аррӏе.com/ Firefox should fix this default setting