Inside butterfly_logs: How Stealer Malware Stole 34,325 Passwords

In July 2025, HEROIC analysts found butterfly_logs 658count data actively circulating in dark web criminal communities after an anonymous Telegram user uploaded the stealer log file publicly. The dataset contains 34,325 records exposing email addresses, plaintext passwords, and the URLs of sites where each credential was captured by infostealer malware running silently on victims' devices. Every record represents a real person whose login credentals were harvested without any warning, notification, or visible sign of infection on their machine. HEROIC has verified this dataset and confirmed it is genuine and actively being traded by threat actors.

Why This Is Dangerous for Anyone in the butterfly_logs Dataset

Stealer logs like butterfly_logs are more immediately dangerous than most data breaches because the passwords they contain are fully readable plaintext -- no cracking required. The moment a criminal downloads butterfly_logs, they can begin testing all 34,325 credential pairs against email providers, banking apps, shopping accounts, and any other service where the victim might have reused that password. The included URLs tell attackers exactly which website each password was originally captured from, removing all guesswork from the process. Victims who have not changed their passwords since July 2025 remain at risk right now.

What Was Exposed

• Email Addresses: Account identifiers enabling criminals to target each victim across every online service linked to that email address
• Plaintext Passwords: Fully readable passwords captured at the moment of login by infostealer malware, usable immediately without any decryption or cracking
• URLs: The exact web addresses where each credential pair was stolen, giving attackers a verified map of which services each victim uses

Why This Matters: Stealer Logs Fuel Mass Account Takeover

When 34,325 sets of credentials circulate on the dark web, the damage is not limited to one wave of attacks. Stealer log datasets get purchased by multiple criminal buyers, bundled into larger combo lists, and retested against new platforms for years. A victim whose credentials appeared in butterfly_logs in July 2025 may encounter account lockouts or fraudulent activity months or years later when their data gets recycled into a fresh credential stuffing campaign. Password reuse is what turns a single stolen record into cascading losses across banking, email, retail, and social accounts -- all traced back to one silent malware infection.

How Stealer Log Malware Works: The butterfly_logs Attack Explained

Understanding how butterfly_logs was assembled reveals why infostealer malware is so devastatng. The attack begins when a victim unknowingly runs malicious software -- often disguised as a cracked application, a pirated game mod, or a fake productivity tool downloaded from an unofficial source. Once executed, the malware silently scans every browser on the device, extracting all saved usernames, passwords, and session cookies. It also records the URL associated with each credential, creating a complete dossier of the victim's online identity. The entire process takes seconds and produces no visible symtoms. The collected data is then packaged into a log file and transmitted to criminal infrastructure, where it is bundled with thousands of other logs and distributed through Telegram channels like the one that released butterfly_logs 658count.

Check If You Are in the butterfly_logs Leak

HEROIC's free dark web scanner has indexed over 400 billion exposed records, including stealer log collections like butterfly_logs 658count. Visit heroic.com now and enter your email address to find out immediately whether your credentials appear in this dataset or any other breach HEROIC monitors. The scan is completely free and requires no account creation. If your email is found in butterfly_logs or any related stealer log, HEROIC provides specific, step-by-step guidance to help you regain control of your accounts and prevent further harm.