UP_KURZL0G Data Breach: 842,283 Passwords Leaked, Act Now

HEROIC analysts confirmed a massive stealer log, tracked as UP_KURZL0G, hit Telegram in October 2025. The number is big: 842,283 records exposed, including email addresses, plaintext passwords, and the exact URLs those logins unlock. This is not a small leak. It is one of the largest stealer logs HEROIC has flagged this year.

Why the UP_KURZL0G Leak Is an Immediate Threat

Plaintext means readable. No cracking, no decrypting, no delay. Whoever holds this file can log into 842,283 accounts right now, today, this minute.

The size of this leak means the odds are high that your information, or someone you know, is sitting inside it.

What Was Exposed in UP_KURZL0G

• Email addresses linked to real accounts
• Plaintext passwords with zero protection
• URLs pointing to the exact site each login opens

Every single one of the 842,283 records is a ready-made login. Nothing stands between a criminal and the account it belongs to.

Why You Need to Act Now

Reused passwords turn one leak into many. Criminals take email and password pairs from files like UP_KURZL0G and blast them at banks, email accounts, and shopping sites within hours, a tactic called credential stuffing.

Wait untill it's too late and the result is account takeover, drained bank accounts, or a stolen identity. This is not a hypothetical, it happens fast once a leak this large starts circulating.

How This Stealer Log Was Built

UP_KURZL0G came from infostealer malware, malicious software that infects a device through a cracked download, fake update, or phishing link.

The malware harvests every saved password, autofill entry, and open session in the browser, then dumps it all, website, username, password, into one massive file. Files this size are usually stitched together from thousands of infected devices before being dropped on Telegram.

The bigger the file, the faster it spreads, and the less time you have to react.

Check If You Are Affected, Right Now

Do not wait to recieve a fraud alert before you take this seriously. HEROIC's free breach scanner checks your email and passwords against a database of more than 400 billion leaked records in seconds.

Scan now, change any reused passwords immediatly, and turn on multi-factor authentication. With a leak this size, minutes matter.