Here's a tester for the new punycode phishing attack: https://www.xn--80ak6aa92e.com/

If your browser takes you to an SSL-secured site that it shows you as https://www.apple.com/

then your browser has problems.

More info: http://thehackernews.com/2017/04/unicode-Punycode-phishing-attack.html

Article has instructions on fixing in Firefox. I tested in Chrome Canary (Chrome v 60) and it's fixed there too.