The PremCloud 400 Breach Put 4,204 Stolen Email and Password Pairs Online in November 2023

HEROIC's threat intelligence team discovered a stealer log file uploaded to a public Telegram channel on November 10, 2023. The file, known as PremCloud 400 and attributed to an anonymous Telegram user, contained 4,204 records tied to compromised endpoints. Each record included an email address, a plaintext password, and a URL, pointing to credentials harvested directly from infected devices. This type of exposure is particularly dangerous because the passwords were stored in plain text, meaning anyone who obtained the file could use them immediatley without any technical skill or additional effort.

Why This Is Dangerous

Stealer logs are among the most efficient tools in a cybercriminal's playbook. Once a device is infected with infostealer malware, every password saved in a browser or application can be captured and packaged into a log file. That file is then shared or sold, often on Telegram or dark web forums, where other criminals use it to break into accounts at scale. Because the passwords in this breach were plaintext, there was no encryption to overcome. Anyone who downloaded that Telegram file had immediate, usable access to thousands of credentials. The risk of credential stuffing attacks and account takeover is extremely high for anyone whose data appeared in this leak.

What Was Exposed

The following types of personal and account data were included in the PremCloud 400 stealer log file:

• Email Addresses
• Plaintext Passwords
• URLs (indicating the sites or services the credentials belong to)

Why This Matters

Four thousand two hundred four exposed records may not make headlines, but for each affected person the consequences are very real. Plaintext passwords combined with email addresses and the specific URLs where they were used gives attackers a precise roadmap into your accounts. If you reuse the same password across multiple services, one exposed credential can set off a chain reaction. Unauthorized access to email can lead to password resets on banking, shopping, and social media accounts. The data from this leak may have already been traded or sold multiple times since November 2023, meaning your credentials could have circulated through criminal networks for years without your knowledge. Stealer log data does not expire when people fail to change their passwords, making these records valuable to attackers long after the original theft occured.

How Stealer Logs Work

A stealer log is created when malware silently infects a device and copies sensitive information without the user noticing. The malware, often called an infostealer, targets passwords saved in browsers like Chrome and Firefox, autofill data, session cookies, and active login credentials. Once it has collected what it needs, the malware packages the data into a structured log file and sends it to the attacker. That file is then distributed through channels like Telegram, where it can be downloaded freely or traded for value. Devices are frequently compremised through phishing links, malicious software downloads, or pirated applications. The device owner often has no indication that anything is wrong, which is why checking known breach databases is the most reliable way to learn whether your credentials were captured.

Check If You Are Affected

HEROIC offers a free scanner that checks your email address against more than 400 billion leaked records, including stealer log files like PremCloud 400. If your credentials appeared in this breach or any other known leak, our tool will flag it instantly so you can take action before your accounts are targeted. The most effective steps after a credential exposure are changing your password immediately, enabling two-factor authentication on every account that offers it, and using a password manager to avoid reuse across services. Do not wait for a notification that never comes. Run a free scan now and find out exactly what data of yours is circulating in known breach databases.