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Truncated URLs Look to Make Big Dent in Phishing

The approach is a long time in coming and will test the premise that users can more easily detect a suspicious domain from the name alone.

Google’s Chrome86 browser is  about to get tested with a new look and feel to help thwart phishing attacks. The browser will only display the primary domain name in the URL, reducing the amount of information displayed to the user so they may hone in on the domain alone. This also reduces the amount of URL real estate used by phishers to trick victims into thinking they are browsing at an intended brand site. 

This is a good thing for several reasons. Google recognizes the growing threat of phishing and is taking a bold step contributing to reducing its prevalence and effectiveness. Few companies aim to protect their customers from phishing, and most only concern themselves with their employees. But they should be very concerned, as is Google. The problem is a real threat beyond corporate networks and any technical solutions, no matter how limited, and contributes to increasing awareness and reducing the danger of the problem. 

The approach is perhaps a long time in coming, but it will be tested not only by users, but the phishers as well. The premise is that users will more easily detect a suspicious domain from the name alone. However, phishers have recently deployed obfuscation and evasion strategies to hide their spoofed sites within legitimate domains. This has become a growing problem, as recognized by many including Microsoft discussing the issue  in a recent post. 

Phishers inevitably will devise measures to counter this browser truncated URL-based defensive strategy by employing domain names that might cause confusion for the user and Google. The cat-and-mouse game hasn’t ended, it has become more sophisticated. Phishers will be creative in finding ways to leverage, for example, third-party redirection as a way to confuse and confound the user,  like this recent example reported by Fortinet.
The approach of displaying the domain name in a truncated URL may bring users to recognize a potential phishing URL more easily, but it may be less easy to see and less effective on a mobile device, which is growing in recent years as a major vector. Clearly, the approach has no bearing on the growing “smishing” vector where phishing URLs are delivered in text messages. Furthermore, phishing campaigns are moving more to the cloud by leveraging cloud storage which will not be addressed at all by a browser’s URL display. 

Google announced the new browser function as a test, largely to determine whether there will be undue confusion by legitimate companies who use third-party domains, for example, which could potentially increase false positives, especially those reported to Google as spam. The last time Google mucked with the URL by removing “www,” a lot of the Internet broke. The safe browsing feature will have to be watched for too many errors. This begs the question whether attackers can leverage user mistakes to launch denial-of-service attacks against legitimate sites. It will be interesting to see how phishers will leverage this feature and the consequences derived from this inevitable misuse. 

A word of caution: Google’s well-intentioned approach continues to put the burden on the user to recognize phishing. There may be an increase in users who improve their own detection, but as breach after breach teaches, even well-educated users still fall victim to the trick-and-click strategy. It is undoubtedly the case that users will not inspect 100% of the URLs displayed anyway.

Thank you, Google. It is a laudable attempt to provide a potentially useful new feature of Chrome that will make it easier for users to identify phishing and other scam sites on their own. My only concern is that this is another step in the direction of making the user responsible for avoiding these attacks. What I’d like to see start happening is industry stepping up and tackling the problem head-on by finding and stopping these attacks automatically using technology. If we could find and shut down attacks as they are just getting started, especially before users can be victimized, we would break the attacker’s economic model and thereby reduce the phishing problem to manageable proportions.

Dr. Salvatore Stolfo is the founder and CTO of Allure Security. As a professor of artificial intelligence at Columbia University since 1979, Dr. Stolfo has spent a career figuring out how people think and how to make computers and systems think like people. Dr. Stolfo has … View Full Bio