The butterfly_logs Leak: 11,550 Passwords Exposed. Yours Might Be One.

HEROIC Analysts Discovered 11,550 Stolen Records in the butterfly_logs Stealer Log

In July 2025, HEROIC analysts identified a stealer log file uploaded to Telegram by an anonymous threat actor. The file, known as butterfly_logs 320count, contained 11,550 records harvested from infected endpoints. The exposed data included email addresses, plaintext passwords, and URLs collected directly from compromised devices before being packaged and distributed on Telegram.

Why This Data Is Dangerous in the Wrong Hands

Stealer log data is among the most actionable information cybercriminals can obtain. Unlike older breached databases, stealer logs are fresh and precise. Attackers who recieve this kind of data can immediately attempt to log in to email accounts, banking portals, and corporate systems using the stolen credentials. Because the passwords are in plaintext, there is no cracking required. The URLs in the log also tell attackers exactly which sites the victim was using, making targeted attacks far more efficient.

What Was Exposed in the butterfly_logs Breach

• Email Addresses
• Plaintext Passwords
• URLs (browsed or saved in the infected browser)

Why This Breach Matters

When email addresses and plaintext passwords are exposed together, the risk of credential stuffing attacks becomes very real. Attackers load stolen pairs into automated tools and test them against hundreds of popular websites in seconds. Even if only one or two of those logins succeed, the attacker gains access to accounts holding personal data, payment information, or sensitive communications. Identity theft and financial fraud are common outcomes. This breach is also a reminder that stealer malware targets everyday users, not just large organizations.

How Stealer Logs Work

A stealer log is created when malware infects a device and silently harvests data stored in the browser or operating system. This type of malware, often called an infostealer, is typically delivered through phishing emails, cracked software, or malicious downloads. Once installed, it collects saved passwords, cookies, autofill data, and browsing history. The collected data is then sent to the attacker, who packages it into log files and distributes them on dark web forums or Telegram channels. The entire process can occured within minutes of infection, and most victims never know their data has been stolen.

Check If Your Information Was Exposed

HEROIC offers a free personal data scanner that searches across more than 400 billion exposed records, including stealer log data like the butterfly_logs breach. If your email address or password was swept up in this or any seperate breach, you deserve to know. Run a free scan at HEROIC and take back control of your digital security before attackers have a chance to use what they already have.