If You Reuse Passwords, the Monster Cloud Stealer Log Should Worry You

HEROIC analysts identified a stealer log tied to Monster Cloud that surfaced on a Telegram channel on November 16, 2023. The log contained 5,012 records made up of email addresses, plaintext passwords, and the URLs of the sites those credentials belonged to.

Why This Stealer Log Is Dangerous

A stealer log comes directly from malware that infected a device and recorded saved logins in real time, rather than from a company's own systems being hacked. Because each record pairs a URL with a matching email and password, an attacker can identify exactly which account a credential unlocks and log in immediately, with no cracking required.

What Was Exposed in This Stealer Log

• Email addresses
• Plaintext passwords
• URLs tied to each login
• 5,012 total records

Why This Matters if You Reuse Passwords

If a password in this log was reused on another account, that account is exposed too. Attackers routinely feed exposed email and password pairs into credential stuffing tools, testing the same login across banking sites, email providers, and other services. Because these passwords were captured in plaintext, they work immediately, raising the risk of account takeover, financial fraud, and identity theft.

How a Stealer Log Like This Gets Made

Stealer logs are produced by information-stealing malware that infects a device, often through a malicious download, phishing link, or cracked software. Once installed, the malware harvests saved passwords, browser autofill data, and active login sessions, then sends that data back to whoever controls it. The resulting file is then packaged and shared on Telegram channels, exactly like the one where this Monster Cloud log appeared.

Check If You Are Affected

Because stealer logs capture whatever was saved on an infected device at the time, it is worth checking whether your email address shows up in this or other exposures. HEROIC's free breach scanner searches a database of more than 400 billion leaked records so you can find out quickly and change any passwords that need it.