FireFox fans across the world, grab the Kleenex!
According to a paper recently published by Eric Johanson of the Shmoo Group, users on most Mozilla-based browsers (Firefox 1.0, Camino .8.5, Mozilla 1.6, etc), Safari 1.2.5, Opera 7.54, Omniweb 5 are victim to a complex International Domain Name [IDN] spoof.
This new attack allows an attacker/phisher to spoof the domain/URLs of businesses. Every recent gecko/khtml based browser implements IDN (which is just about every browser except for Internet Explorer). The Smoo Group have created a proof of concept where the links are directed at "http://www.pаypal.com/", which the browsers punycode handlers render as http://www.xn--pypal-4ve.com.
According to the group there is however an easy to way to detect you're under a spoof attack, cut & paste the url you are accessing into notepad or some other
tool (under OSX, paste into a terminal window) which will allow you to view what character set/pagecode the string is in. You can also view the details of the SSL cert etc.
You can disable IDN support in Mozilla products by setting 'network.enableIDN' to false. There is no known workaround for Opera or Safari. Vendor responses have been varied with VeriSign and Apple failing to respond but Opera believing they have correctly implemented IDN, and will not be making any changes (oops). Mozilla are currently working on finding a good long-term solution. The company provided a clear workaround for disabling IDN temporarily until it can better address the issue.
This latest exploit will provide spammers with a way to trick FireFox, Opera and Safari users into thinking they're on a certain website. Commonly known as Phishing this latest attack by spammers and hackers is frighteningly common.
Update: Many users are reporting the config change in Firefox does not work, currently there is no fix for Firefox.
Neowin's Brandon Goode Contributed to this report
To see if you're vulnerable, take a look here: http://www.shmoo.com/idn/
network.enableIDN set to false works fine for me...