Chrome+Firefox Phishing Attack Uses Domains Identical to Known Good

This variant of a phishing attack uses unicode to register domains that look identical to real domains. These fake domains can be used in phishing attacks to fool users into signing into a fake website, thereby handing over their login credentials to an attacker.



As you can see both of these domains appear identical in the browser but they are completely different websites. One of them was registered by us, today. Our epic.com domain is actually the domain https://xn--e1awd7f.com/ but it appears in Chrome and Firefox as epic.com.

How is this possible? The xn-- prefix is what is known as an ‘ASCII compatible encoding’ prefix. It lets the browser know that the domain uses ‘punycode’ encoding to represent Unicode characters. In non-techie speak, this means that if you have a domain name with Chinese or other international characters, you can register a domain name with normal A-Z characters that can allow a browser to represent that domain as international characters in the location bar.
What we have done above is used ‘e’ ‘p’ ‘i’ and ‘c’ unicode characters that look identical to the real characters but are different unicode characters. In the current version of Chrome, as long as all characters are unicode, it will show the domain in its internationalized form.



How to fix this in Firefox:

In your firefox location bar, type ‘about:config’ without quotes.
Do a search for ‘punycode’ without quotes.
You should see a parameter titled: network.IDN_show_punycode
Change the value from false to true.
Now if you try to visit our demonstration site you should see:





Currently we are not aware of a manual fix in Chrome for this. Chrome have already released a fix in their ‘Canary’ release, which is their test release. This should be released to the general public within the next few days.

Until then, if you are unsure if you are on a real site and are about to enter sensitive information, you can copy the URL in the location bar and paste it into Notepad or TextEdit on Mac. It should appear as the https://xn--….. version if it is a fake domain. Otherwise it will appear as the real domain in its unencoded form if it is the real thing.

Read more here:
Chrome and Firefox Phishing Attack Uses Domains Identical to Known Safe Sites

Bree said:

I knew there was a good reason I stick with IE - it shows the raw 'punycode’.

Oh... and so does Edge.

Is this confirmed for Edge? Currently with it... This is nasty one

Thanks for the heads up @simrick .

AndreTen said:

Is this confirmed for Edge? Currently with it... This is nasty one

Thanks for the heads up @simrick .

You can check out Edge, or any browser, using their sample site (in the original article). For me, Edge shows the correct site address.

eLPuSHeR said:

Thanks for posting. Fix applied to Firefox.

Browsing in Edge on Insider preview and Fox fixed. Is Firefox syncing this settings? Anybody knows?

AndreTen said:

Browsing in Edge on Insider preview and Fox fixed. Is Firefox syncing this settings? Anybody knows?

I have no idea, as I don't sync. Maybe someone else who does can answer that. Would be good to know.