Stealer Log Led to 4,401 Stolen Logins: The Furnas.com.br Explained

HEROIC analysts identified this stealer log on 10-Jun-2026. The breach exposed 4,401 records, with stolen data including email addresses, plaintext passwords, and URLs. The source is identified as furnas.com.br, the domain of Furnas Centrais Eletricas, a major Brazilian electricity generation and transmission company.

Why This Is Dangerous

Credentials linked to critical infrastructure organizations like an electricity utility are high-priority targets for cybercriminals and nation-state actors. This stealer log exposes 4,401 plaintext passwords alongside the URLs where they were active, giving attackers direct insight into which systems and services were in use. Anyone whose credentials appear here is also at risk if those same passwords protect personal accounts on other platforms.

What Was Exposed

• Email Addresses
• Plaintext Passwords
• URLs (the specific websites where credentials were active)

Why This Matters

Infrastructure sector employees are frequently targeted in spear phishing and business email compromise attacks. Stolen credentials from a utility company can be used to impersonate employees, gain access to vendor portals, or probe connected systems. Even if the stolen accounts are personal rather than corporate, attackers may attempt to use them to establish a foothold for further attacks against the organization.

How Stealer Logs Work

A stealer log is produced by malware that infects an employee's or contractor's personal or work computer. The malware reads every password stored in the browser, captures the corresponding website addresses, and sends all of it back to the attacker automatically and invisibly. The attacker then distributes this data through private Telegram channels, making it available to a wide criminal audience.

Check If You Are Affected

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