The klaus_cloud_public 500logs Dump Contains Exactly 14,037 Email and Password Pairs

HEROIC analysts documented a stealer log upload to a public Telegram channel on October 28, 2023, posted under the label klaus_cloud_public 500logs. The file contained 14,037 records pulled from compromised endpoint devices. Each record paired an email address with a plaintext password and one or more URLs, representing real accounts on real services that were logged in at the moment the malware ran on the victim's machine. The data was posted publicly on Telegram, where it was freely available to anyone who wanted to use it.

Why Plaintext Passwords Make the klaus_cloud_public Leak Immediately Exploitable

Most large-scale data breaches involve hashed passwords, which require significant effort to reverse into usable form. This log contains none of that protection. Every password is written in plain text, the way you would type it into a login box. That means anyone who downloaded this file can test those credentials against websites right now, without any cracking tools or technical expertise. The URLs included in each record make the situation worse: attackers already know which services each victim was using, giving them a shortlist of accounts to target first.

What Was Exposed in the 500logs File

• 14,037 email addresses paired with their corresponding passwords
• Plaintext passwords with no encryption or hashing applied
• URLs showing which websites and services the victims were logged into
• API host addresses that may point to business or developer platforms
• Endpoint data identifying the infected devices

Why This Matters: The Chain from Stolen Login to Financial Loss

A stolen plaintext password is the easiest possible entry point for an attacker. Once someone has your email and password, they can try that combination on your bank, your email provider, your employer's login portal, and dozens of other services. Credential stuffing attacks are automated and fast, often testing thousands of login combinations per minute. If any of those attempts succeed, the attacker is inside your account before you have any idea something went wrong.

From there, the consequences multiply quickly. Email access means password resets on every other service. Bank access means unauthorized transfers. The presense of API host data in this log suggests some victims may have exposed developer or business system access, putting not just personal accounts but entire organizations at risk.

How Stealer Logs Are Created and Why Telegram Is the Distribution Method

Stealer logs are created when malware infects a device and harvests credentials stored in browsers, email clients, and other applications. The malware collects everything it finds, including saved usernames and passwords, session cookies, and browsing history, then sends it back to the attacker. The data is compiled into a log file and either sold or, in cases like this, given away on Telegram. Telegram is popular for this because it allows large file sharing, has minimal content moderation for private or semi-public channels, and lets bad actors reach a wide audience quickly. The label "500logs" likely refers to a batch size, suggesting the uploader was distributing data in organized collections.

Check If Your Credentials Are in the klaus_cloud_public 500logs Data

HEROIC's breach scanner searches more than 400 billion compromised records, including stealer logs like the one posted under the name Klaus Cloud Public. If your email address is in this dataset, HEROIC will show you the breach details so you know exactly what was exposed and what to do next. Run a free search on your email address now at HEROIC's breach scanner and find out if your accounts are at risk.