How the “19-05-26” Stealer Log Leaked 16,244 Records

What HEROIC Analysts Found

It starts with malware quietly running on infected computers, collecting logins over time. Eventually, that stolen data gets bundled into a single file. HEROIC analysts traced one such file, named "19-05-26," to a Telegram upload on May 18, 2026. The file contains 16,244 records, each pairing an email address with a plaintext password and the website URL the login belonged to.

Why This Is Dangerous

By the time a file like this reaches Telegram, the credentials inside it are already exposed and ready to use. Because the passwords are stored in plaintext, an attacker can copy any of the 16,244 records and attempt to log in immediately, with no cracking or guessing required.

What Was Exposed

• Email addresses
• Plaintext passwords
• Website URLs tied to each login

Why This Matters

A file of this size means thousands of people are at risk if they reused their password anywhere else. Attackers commonly take large stealer logs like this one and run them through automated credential stuffing tools, testing the same email and password against banking, email, and shopping sites.

How Stealer Logs Work

The process usually begins when a victim downloads pirated software, installs a fake update, or opens a malicious attachment. The hidden malware then scans the browser for saved passwords and active login sessions, sending everything back to the attacker. Once enough data accumulates, it gets packaged into a dated file, like 19-05-26, and shared or sold on Telegram.

Check If You Are Affected

HEROIC's free breach scanner checks your email against more than 400 billion leaked records, including large stealer log dumps like this one. Run a scan today to see if your credentials were part of this leak.