The CNZZ Dump Contains 945,054 Exposed Credential Records

CNZZ was a major Chinese web analytics and advertising platform widely used by website owners across China to track traffic and user behavior. On February 16, 2012, the site suffered a database breach that exposed 945,054 user accounts. The stolen records included email addresses, usernames, and MD5 password hashes. The data has circulated on dark web forums for over a decade and continues to appear in aggregated breach collections.

Why CNZZ Breach Is Dangerous

Nearly one million accounts is a substantial leak, but the real concern is the password format. MD5 hashing without salting is one of the weakest protections available, and modern cracking tools can break most MD5 passwords in minutes or hours. Once cracked, those credentials are used in credential stuffing attacks against other platforms. CNZZ users who registered with an email and password they also use elsewhere are at risk, even if they haven't thought about this account in over a decade.

What Was Exposed in the CNZZ Leak

• Email Address
• Password Hash
• Username

Why This CNZZ Data Puts You at Risk

Advertising and analytics platforms often attract web professionals, business owners, and developers. If your CNZZ credentials were in this dump, the same email and password may unlock work accounts, business dashboards, or admin panels on other services. MD5 hashes from dumps like this get loaded into seperate cracking sessions and resolved quickly, turning password hashes into ready-to-use plaintext credentials sold to attackers looking for easy account access.

How Database Breaches Work

In a database breach, an attacker gains unauthorized access to a site's backend and pulls the user database. The breach occured at CNZZ in February 2012, likely through a vulnerability in the platform's server or web application. Over 945,000 records were extracted, each containing an email address, username, and password hash. That data was packaged and distributed on dark web marketplaces, where it remains available to buyers immediatly and continues to circulate today.

Check If Your Data Was Exposed

HEROIC's free breach search checks your email against 400 billion+ compromised records, including data from the CNZZ dump. Search now to find out if your credentials were part of this breach, and update your passwords before someone uses them to access your other accounts.