How the Monster Cloud Free 15 Stealer Log Led to 17,715 Stolen Logins on Telegram

HEROIC analysts identified a stealer log tied to a service called Monster Cloud Free 15 after it was uploaded to a Telegram channel in November 2023. The dump exposed 17,715 records harvested from infected devices, including email addresses, plaintext passwords, and URLs. The naming pattern suggests this was one release in a larger series of similarly labeled log files distributed by the same uploader over time.

Why This Is Dangerous

Every password in this dump was stored and leaked in plaintext, meaning there is no cracking step required before an attacker can use it. Anyone who downloaded this file could immediately begin testing the exposed email and password pairs against cloud services and other websites. That kind of direct exposure removes the delay that normally gives victims time to react before their credentials are misused.

What Was Exposed

• Email addresses from infected devices
• Plaintext passwords with no encryption or hashing
• URLs tied to cloud service accounts and endpoints
• 17,715 total records in the dump
• Data uploaded to Telegram on November 1, 2023

Why This Matters

Cloud account credentials are especially valuable because they often unlock file storage, connected apps, and business tools beyond a single login. If any of the affected users reused their Monster Cloud Free 15 password on a work account or another service, that exposure extends well past the original leak. Because stealer logs like this one are distributed outside of any official breach process, most victims will never receive a notification and have to check for themselves.

How Stealer Log Breaches Work

A stealer log is generated by malware that infects a device, typically through phishing emails, cracked software, or malicious browser extensions, and then silently harvests saved credentials, cookies, and visited URLs from the browser. The malware packages this data into a structured log file and sends it back to the attacker, who then shares or sells it through Telegram channels and underground forums where other criminals can download it.

Check If You Are Affected

HEROIC's free breach scanner searches more than 400 billion leaked records, including stealer log dumps like Monster Cloud Free 15. Enter your email address to find out if your credentials appeared in this breach or any other known data leak, and change any exposed passwords right away.