How to eliminate the use of stolen passwords

Today we’re releasing Blackfish, a system that proactively protects companies from credential stuffing before an attack takes place. Normally, credential stuffing starts with a data breach at one major company (“Initial Victim”), and continues when a criminal then uses the stolen data (usernames and passwords) against dozens or even hundreds of different companies (“Downstream Victims”). Usually, many months or years pass before the Initial Victim realizes and discloses the initial data breach, and in that time, criminals are able to successfully attack huge numbers of Downstream Victims. Later, once the Initial Victim does disclose the breach, the Downstream Victims start matching the username/password pairs from the Initial Victim against their own user databases, and resetting any passwords that match. The whole process can take years and results in hundreds of millions of dollars worth of fraud and brand damage.

Blackfish changes all that. From the very first moment a criminal attempts to use stolen usernames and passwords, Blackfish begins monitoring and protecting matching accounts at other companies. So, while under normal circumstances a criminal can get hundreds of chances to monetize the stolen usernames and passwords, with Blackfish in place, criminals get far fewer chances.

You may be wondering how Blackfish can accomplish all this. Explaining that requires a little background on Shape Security.

We founded Shape six years ago to answer a simple question: is a visitor to a web or mobile app an actual human being? This simple question proved to be an important one. As we perfected our ability to answer it, we started eliminating enormous amounts of fraudulent traffic from the largest web and mobile apps in the world — often 90% or more of the login traffic from a Fortune 100 web application.

Today, we are the primary line of defense for many of the largest organizations around the world. Our customers include: three of the top four banks, three of the top five airlines, two of the top three hotel chains, and numerous other leading companies and government agencies.

We secure all of those large organizations in a centralized way, directly delivering the security outcome of eliminating fraudulent traffic. That centralized security capability is also the heart of Blackfish, and allows Blackfish to see stolen usernames and passwords in use far before anyone else ever knows about them (including the Initial Victim).

Think about it: if you were a criminal and managed to steal all the usernames and passwords from a major corporation, where would you try them out? If you’re like most criminals, the answer is that you’d try them on the largest banks, airlines, hotels, and retail sites in the world. That’s what happens in practice, and when it does, that’s also when Blackfish sees the very first such attack, and sets about protecting all username/password pairs that happen to match on other large websites.

Blackfish does all this before the original data breach is reported or even detected by the Initial Victim company.

The problem with looking for credentials on the dark web

You can scour the dark web to find user credentials, but one of the greatest dangers companies face today is the long window of time between when breaches occur on third-party websites like Yahoo, and when those breaches are discovered and announced. Instead of hoping that stolen passwords will appear in the dark web in time to be useful, Blackfish autonomously detects credential stuffing attacks on the largest, most targeted websites in the world, identifies newly stolen credentials, and nullifies them globally. That stolen data becomes useless to cybercriminals.

How does it work?

Shape has grown into one of the largest processors of login traffic on the entire web. We have built machine learning and deep learning systems to autonomously identify credential stuffing attacks in real-time. These systems now generate an important byproduct: direct knowledge of stolen usernames and passwords when criminals are first starting to exploit them against major web and mobile apps. What this means is that we see the stolen assets months or years before they appear on the dark web.

Blackfish’s knowledge base of compromised credentials is built with maximum security in mind. To ensure that its knowledge base is secured, Blackfish does not store any credential information but instead leverages Bloom filters to create probabilistic data structures to perform its operations. As a result, the compromised credentials themselves are not stored anywhere and Blackfish can use the information about compromises to improve security while maintaining full data privacy.

What good is a stolen password if you can never use it?

For better or for worse, memorized secrets (a.k.a. “passwords”) are the most widely used authentication mechanism online. As such, having access to millions of stolen passwords (over 3.3 billion were reported stolen in 2016 alone) allows cybercriminals to easily take over users’ accounts on any major website. They do this with credential stuffing attacks, which take stolen passwords from website A and try them on website B to see which accounts the same email addresses and passwords will unlock. Cybercriminals can do this reliably with a typical 1–2% success rate, allowing them to seize the value in bank accounts, gift card accounts, airline loyalty programs, and other accounts, which they can then monetize for a predictable ROI.

Since credential stuffing attacks are responsible for more than 99.9% of account takeover attempts, if we identify the stolen credentials that are used in these attacks, and invalidate them across other websites, we change the economics for cybercriminals significantly. If their 1–2% success rate now drops by two orders of magnitude or more, their “business” no longer functions. At that point, the cybercriminal has no choice but to try to obtain new stolen passwords. If those new passwords are similarly detected and invalidated, it will become clear to the criminals that the economics of their scheme have been broken. We think that over time, Blackfish will end credential stuffing for everyone.

We are all very excited at Shape to announce this system and our vision to make credential stuffing attacks a thing of the past. You can learn more on our website and contact us when your company is ready to try Blackfish.

Originally published at blog.shapesecurity.com on November 7, 2017.