How the MyCube.ru Leak Exposed 206,348 Plaintext Passwords

HEROIC analysts identified a dataset attributed to MyCube.ru, a now-defunct Russian art gallery website that once showcased work from independent creators, that was shared on a Telegram channel in April 2025. The exposure affects 206,348 accounts and includes email addresses paired with plaintext passwords, meaning the passwords were stored and leaked in fully readable form.

Why This Is Dangerous

With plaintext passwords, there is nothing for an attacker to crack or decode. Each email and password pair is ready to use the moment it is downloaded, and with more than 200,000 accounts involved, this is a large, immediately usable list for anyone looking to break into other accounts.

What Was Exposed

• Email addresses
• Plaintext passwords

Why This Matters

A leak of this size is especially valuable to attackers when it is folded into combolists, large files that pair millions of emails and passwords from many different breaches. Automated tools run those combolists against banking sites, email providers, and social platforms in a technique called credential stuffing. If you ever used your MyCube.ru password anywhere else, that reused password could now be the key to your email, your bank, or your social accounts, opening the door to account takeover, identity theft, or financial fraud.

How This Database Leak Reached Telegram

This incident is classified as a database leak. That typically means an attacker gained direct access to MyCube.ru's user database and exported the records in bulk, with no hashing or encryption protecting the passwords in the first place. The data was then shared on a Telegram channel, a common distribution point for stolen datasets because it lets criminals reach a wide audience quickly. Because MyCube.ru is now defunct, there is no company left to force a password reset or notify affected users.

Check If You Are Affected

If you ever created an account on MyCube.ru or reused that password elsewhere, it is worth checking your exposure now. HEROIC's free breach scanner searches a database of more than 400 billion leaked records, showing you instantly whether your email or password has surfaced in this or any other breach so you can change it before someone else uses it.