The Monster Cloud Free 4 Leak: 28,624 Passwords Exposed. Yours Might Be One.

In October 2023, analysts monitoring Telegram-based threat actor channels identified a stealer log file called Monster Cloud Free 4, uploaded publicly by an anonymous user. The file contained 28,624 records stolen from compromised devices across the United States. Each record included an email address, a plaintext password, and a URL tied to an API host or web application. This is one of the larger stealer log releases in this series, and the data was made freely available, meaning tens of thousands of people had their login credentials circulating in criminal networks with no warning and no way to know.

Why This Is Dangerous

With 28,624 plaintext passwords in a single file, attackers have an enormous ready-to-use credential list requiring zero additional work. No cracking, no guessing, no brute force. Every email and password pair can be tested against Gmail, Outlook, banking apps, and corporate logins within minutes using automated tools. The API host URLs included in this log suggest that some victims had access to developer environments, cloud infrastructure, or business applications, elevating the potential impact from personal account takeover to full corporate network compromise. The scale of this leak makes it one of the more consequential stealer log releases from the October 2023 wave.

What Was Exposed in the Monster Cloud Free 4 Leak

• Email addresses
• Plaintext passwords
• API host URLs and endpoint data

Why This Matters

Nearly 29,000 people had their credentials stolen and published without their knowledge. For each of those individuals, the risk extends far beyond the single account where the password was captured. Credential stuffing attacks use these lists to hit dozens of platforms at once, meaning one leaked password can unlock email, banking, streaming, shopping, and workplace accounts in rapid succession. Identity theft and financial fraud are direct outcomes for many victims of stealer log leaks. Because the data spreads so quickly after being posted on Telegram, the window to take protective action is very short.

How Stealer Logs Work

Infostealer malware infects devices through phishing emails, fake software installers, and malicious browser extensions. Once active, it harvests every saved password from the browser, captures login sessions via stolen cookies, records keystrokes on sensitive sites, and collects any API tokens or credentials stored in plain text on the device. All of this is assembled into a compact log file and silently transmitted to the attacker's server. The attacker then bundles and labels the logs, often by category or country, and distributes them freely on Telegram to gain reputation in underground communities or sells them in private markets. Monster Cloud Free 4 is one entry in what appeares to be a recurring series of organized stealer log releases, each targeting cloud-related credentials for maximum value.

Check If You Are Affected

There is no official notification process for stealer log victims. You will not recieve an email from a company telling you your password was stolen, because the theft hapened on your own device. HEROIC's free breach scanner is one of the fastest ways to find out. It checks your email address against more than 400 billion exposed records, including stealer log data like Monster Cloud Free 4. If your credentials are in this file or any other known breach, you'll see the results immediatly. Search your email now and change any passwords that show up before someone else does.