You Think You Can’t Be Phished?

Well, think again. At least if you are using Chrome or Firefox. Don’t believe us? Well, check out Apple new website then, at https://www.apple.com . Notice anything? If you are not using an affected browser you are just seeing a strange URL after opening the webpage, otherwise it’s pretty legit. This is a page to demonstrate a type of Unicode vulnerability in how the browser interprets and show the URL to the user. Notice the valid HTTPS. Of course the domain is not from Apple, it is actually the domain: “https://www.xn--80ak6aa92e.com/“. If you open the page, you can see the actual URL by right-clicking and select view-source.

So what’s going on? This type of phishing attack, known as IDN homograph attacks, relies on the fact that the browser, in this case Chrome or Firefox, interprets the “xn--” prefix in a URL as an ASCII compatible encoding prefix. It is called Punycode and it’s a way to represent Unicode using only the ASCII characters used in Internet host names. Imagine a sort of Base64 for domains. This allows for domains with international characters to be registered, for example, the domain “xn--s7y.co” is equivalent to “短.co”, as [Xudong Zheng] explains in his blog.

Different alphabets have different glyphs that work in this kinds of attacks. Take the Cyrillic alphabet, it contains 11 lowercase glyphs that are identical or nearly identical to Latin counterparts. These class of attacks, where an attacker replaces one letter for its counterpart is widely known and are usually mitigated by the browser:

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Binary Keyboard Is The Purest Form Of Input Device

You may be a hardcore keyboard aficionado whose buckled-spring switches will be pried from your cold dead hands, but there is a new model on the street that relegates your blank-key Das Keyboard or your trusty IBM Model M to the toy chest.

The new challenger comes from Reddit user [duckythescientist], who has created a minimalist three-key binary keyboard. It features a 0 key, a 1 key, a return key, and nothing else. Characters are entered as ASCII or Unicode, and the device emulates either a QWERTY or Dvorak keyboard layout to the host computer’s USB interface. It couldn’t be a simpler layout to learn, though we’d concede that not everyone has the entire binary Unicode table memorised.

The keys are mounted in a custom 3D printed case, and the electronics come from the creator’s own “tinydev” board based on an ATtiny85. All the code is available in a GitHub repository, and there is a very short video of its Unicode ability below the break.

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UTF-8 – “The most elegant hack”

While it may not look like much, the image above is a piece of the original email where [Ken Thompson] described what would become the implementation of UTF-8. At the dawn of the computer age in America, when we were still using teletype machines, encoding the English language was all we worried about. Programmers standardized on the ASCII character set, but there was no room for all of the characters used in other languages. To enable real-time worldwide communication, we needed something better. There were many proposals, but the one submitted by [Ken Thompson] and [Rob ‘Commander’ Pike] was the one accepted, quite possibly because of what a beautiful hack it is.

[Tom Scott] did an excellent job of describing the UTF-8. Why he chose to explain it in the middle of a busy cafe is beyond us, but his enthusiasm was definitely up to the task. In the video (which is embedded after the break) he quickly shows the simplicity and genius of ASCII. He then explains the challenge of supporting so many character sets, and why UTF-8 made so much sense.

We considered making this a Retrotechtacular, but the consensus is that understanding how UTF-8 came about is useful for modern hackers and coders. If you’re interested in learning more, there are tons of links in this Reddit post, including a link to the original email.

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sslstrip, hijacking SSL in network

Last week at Black Hat DC, [Moxie Marlinspike] presented a novel way to hijack SSL. You can read about it in this Forbes article, but we highly recommend you watch the video. sslstrip can rewrite all https links as http, but it goes far beyond that. Using unicode characters that look similar to / and ? it can construct URLs with a valid certificate and then redirect the user to the original site after stealing their credentials. The attack can be very difficult for even above average users to notice. This attack requires access to the client’s network, but [Moxie] successfully ran it on a Tor exit node.