Mother of all breaches reveals 26 billion records: what we know so far

The supermassive leak contains data from numerous previous breaches, comprising an astounding 12 terabytes of information, spanning over a mind-boggling 26 billion records. The leak, which contains LinkedIn, Twitter, Weibo, Tencent, and other platforms’ user data, is almost certainly the largest ever discovered.

There are data leaks, and then there’s this. A supermassive Mother of all Breaches (MOAB for short) includes records from thousands of meticulously compiled and reindexed leaks, breaches, and privately sold databases. The full and searchable list is included at the end of this article.

Bob Dyachenko, cybersecurity researcher and owner at SecurityDiscovery.com, together with the Cybernews team, has discovered billions upon billions of exposed records on an open instance.

Even though at first the owner of the database was unknown, Leak-Lookup, a data breach search engine, said it was the holder of the leaked dataset. The platform posted a message on X, saying the problem behind the leak was a “firewall misconfiguration,” which was fixed.

• You can check if your data was exposed in historic data breaches using the Cybernews data leak checker. Our team is working hard to update the tool and provide you with means to check if your data was exposed in the MOAB.

According to the team, while the leaked dataset contains mostly information from past data breaches, it almost certainly holds new data, that was not published before. For example, the Cybernews data leak checker, which relies on data from all major data leaks, contains information from over 2,500 data breaches with 15 billion records.

The MOAB contains 26 billion records over 3,800 folders, with each folder corresponding to a separate data breach. While this doesn’t mean that the difference between the two automatically translates to previously unpublished data, billions of new records point to a very high probability, the MOAB contains never seen before information.

Researchers believe that the owner of the MOAB has a vested interest in storing large amounts of data and, therefore, could be a malicious actor, data broker, or some service that works with large amounts of data.

“The dataset is extremely dangerous as threat actors could leverage the aggregated data for a wide range of attacks, including identity theft, sophisticated phishing schemes, targeted cyberattacks, and unauthorized access to personal and sensitive accounts,” the researchers said.

The supermassive MOAB does not appear to be made up of newly stolen data only and is most likely the largest compilation of multiple breaches (COMB).

While the team identified over 26 billion records, duplicates are also highly likely. However, the leaked data contains far more information than just credentials – most of the exposed data is sensitive and, therefore, valuable for malicious actors.

A quick run through the data tree reveals an astoundingly large number of records compiled from previous breaches. The largest number of records, 1.4 billion, comes from Tencent QQ, a Chinese instant messaging app.

However, there are supposedly hundreds of millions of records from Weibo (504M), MySpace (360M), Twitter (281M), Deezer (258M), Linkedin (251M), AdultFriendFinder (220M), Adobe (153M), Canva (143M), VK (101M), Daily Motion (86M), Dropbox (69M), Telegram (41M), and many other companies and organizations.

The leak also includes records of various government organizations in the US, Brazil, Germany, Philippines, Turkey, and other countries.

According to the team, the consumer impact of the supermassive MOAB could be unprecedented. Since many people reuse usernames and passwords, malicious actors could embark on a tsunami of credential-stuffing attacks.

“If users use the same passwords for their Netflix account as they do for their Gmail account, attackers can use this to pivot towards other, more sensitive accounts. Apart from that, users whose data has been included in supermassive MOAB may become victims of spear-phishing attacks or receive high levels of spam emails,” the researchers said.

The leak’s scale is of yet unseen proportions. For example, in 2021, Cybernews reported a COMB that contained 3.2 billion records – only 12% of the supermassive MOAB of 2024.

We are updating the Cybernews data leak checker to include information from the MOAB, which will allow users to see whether their data was included in the largest known data leak. Meanwhile, users are strongly advised to stay vigilant and take care of their cyber hygiene.

Everyone should use strong, hard to guess passwords, generated by reliable password managers, enable multi-factor authentication on all important accounts, keep an eye for phishing and spear phishing attempts, check for password duplicates and immediately set up new protection for accounts that share the same passwords.

Updated on January 29. Information regarding the possible owner of the dataset was added to the article.