When the XSS.IS Combolist surfaced in February 2019, it wasn't just another data breach — it was a curated product. With 2.47 billion records containing email addresses, usernames, and plaintext passwords, this massive compilation represented countless hours of underground market activity: aggregating, cleaning, verifying, and packaging stolen data for maximum profit.
Welcome to the cyber black market, where your personal information has become a tradable commodity.
The Economics of Stolen Credentials
Our intelligence database tracks over 13,600 distinct breaches containing 18.9 billion records. But here's what most people miss: many of the largest "breaches" aren't single security incidents. They're combolists — carefully assembled collections of credentials harvested from multiple sources, then repackaged and sold repeatedly across underground forums.
The Misc Combolists compilation alone contains 1.9 billion records. The Ga$$Pacc Collection adds another 518 million. These aren't breaches in the traditional sense. They're products, assembled by data brokers who operate in the shadows of Telegram channels, dark web forums, and encrypted marketplaces.
When you see a breach with data types listed as "Email Address, Plaintext Password," you're looking at criminal inventory designed for immediate exploitation. No decryption needed. No technical skills required. Ready-to-use credentials that buyers can deploy for credential stuffing attacks within minutes of purchase.
From Breach to Bazaar: The Supply Chain
The journey of your stolen data follows a predictable pattern. First comes the initial compromise — a database vulnerability, a stealer log infection, or a phishing campaign. Our data shows that stealer logs represent 57% of all tracked breaches, reflecting the current criminal preference for malware that harvests credentials directly from infected devices.
These fresh stealer logs appear almost daily. Recent uploads include collections like "Wako_Cloud" and "Everlasting_Cloud," each containing thousands of freshly harvested credentials. The naming conventions reveal their origin: uploaded by Telegram users who operate in private channels where data is shared or sold.
Next, the data gets aggregated. Database breaches (accounting for 30% of incidents) get combined with stealer logs. Duplicates are removed. Credentials are verified against live services. The result? High-quality combolists where buyers know their success rate before purchasing.
Finally, the data enters circulation. It gets posted on forums like Exploit.in (503 million records), AntiPublic (348 million records), and Pemiblanc (344 million records). Some collections, like Verifications.io's 722 million records containing email addresses, phone numbers, and names, get packaged specifically for marketing fraud and social engineering.
The Plaintext Password Economy
Here's a sobering reality: 1,822 breaches in our database contain plaintext passwords. That's 13% of all incidents where your password wasn't encrypted or hashed — it was stored and stolen in perfectly readable form.
Even more concerning, plaintext passwords appear as an exposed data type in 9,530 breaches. This means that across multiple incidents, criminals have immediate access to working credentials. No rainbow tables. No GPU cracking rigs. Just copy, paste, and exploit.
This creates a secondary market for "fresh" credentials. When MySpace's 301 million accounts leaked in 2008 with password hashes, those required technical effort to crack. Modern breaches increasingly skip this step entirely, offering criminals turnkey access to your accounts.
Why Your Old Passwords Still Matter
Collection #1, leaked in January 2019 with 649 million records, illustrates why credential reuse is a criminal's best friend. While it contained older data, the compilation remains valuable because people recycle passwords. A credential stolen from a forum breach in 2015 might still unlock your email account in 2026.
The Weibo breach demonstrates another dimension: 503 million phone numbers. Combined with email addresses and passwords from other sources, this enables sophisticated social engineering. Criminals don't just break into accounts — they call customer service pretending to be you, armed with enough personal details to pass verification questions.
Protecting Yourself in a Compromised World
Understanding the black market mechanics reveals why standard security advice actually matters:
Use unique passwords everywhere. When criminals test stolen credentials, they're betting on reuse. A unique password turns a massive combolist into useless data for your accounts.
Enable two-factor authentication. Even if your password appears in multiple breaches, 2FA blocks automated credential stuffing attacks that fuel the underground economy.
Monitor your exposure regularly. With 7,700 breaches exposing URLs and email addresses, you need to know which of your accounts have been compromised. The data isn't going away — it circulates and recirculates in new combinations.
Check Your Exposure
The cyber black market operates 24/7, continuously monetizing stolen data. Your credentials may already be listed in multiple compilations, traded between criminals, and queued for exploitation attempts.
Don't wait to find out through fraudulent charges or a locked account. Search your email address at LeakedSource to see exactly which breaches have exposed your information. Our database indexes 18.9 billion records from 13,600 breaches — if your data is circulating in underground markets, we'll show you where and what was taken.
Knowledge is your first line of defense in a world where your personal information has become currency.