3870_Japan_KRDCLOUD Leak: 3,829 Passwords, Multiple Accounts at Risk

HEROIC analysts identified a combolist file labeled "3870_Japan_KRDCLOUD" circulated on Telegram in August 2026, containing 3,829 records. Each record pairs an email address with a plaintext password, and many entries also list the URL of the site the login was originally used on.

Why This Is Dangerous

A single leaked password rarely stays contained to one account. Because the passwords in this file are stored in plaintext, an attacker can immediately try the exact combination shown, and then move on to test the same email and password against other services the victim might use, turning one exposed credential into access across several accounts.

What Was Exposed

• Email addresses
• Plaintext passwords
• URLs linked to the original accounts

Why This Matters

Most people reuse a small handful of passwords across many different accounts, from email to banking to online shopping. Once attackers confirm a working password on one service through credential stuffing, they systematically test it elsewhere. That chain reaction can lead to multiple account takeovers from a single leaked credential, along with identity theft and financial fraud wherever payment information is stored.

How a Combolist Leak Works

A combolist like this one is a plain text file of login pairs, typically formatted as email:password, gathered from smaller breaches and leaks before being labeled and posted to a channel like this. Because the format takes no special skill to use, automated tools can run each pair against dozens of different websites in sequence, which is exactly what makes the risk of a single leak spread across multiple accounts so real.

Check If You Are Affected

Since one leaked password can put more than one of your accounts at risk, it is worth checking your exposure directly. HEROIC's free breach scanner searches a database of more than 400 billion leaked records, including combolists like this one, so you can find out quickly and update any passwords you have reused elsewhere.