Someone Has Your Password: 25 Japan Credentials Leaked

HEROIC detected a stealer log file labeled "JP 3" circulating on Telegram in December 2025. While the dataset is small at 25 records, each entry contains a complete set of credentials targeting Japanese users, including their email address, plaintext password, and the URL where the login was captured. For the 25 individuals affected, their accounts are already exposed to anyone who accesses this file.

Even 25 Plaintext Passwords Cause Serious Damage

Every password in this 25-record dataset is stored in plaintext with absolutely no protection. It does not matter that the dataset is small. Each of these 25 credentials represents a real person whose password is now visible to criminals. Attackers do not need large volumes to cause harm. A single working credential can be used to take over an email account, reset passwords on linked services, and gain access to financial accounts or personal data stored in cloud services.

What Was Exposed

• Email Addresses — Japanese user accounts that serve as keys to multiple connected services
• Plaintext Passwords — completely unprotected login credentials visible to anyone with the file
• URLs — the exact websites where each credential was captured by malware

Small Leaks Feed Larger Credential Stuffing Operations

Datasets like JP 3 may seem insignificant on their own, but they are routinely aggregated with thousands of similar small dumps to build massive credential lists for automated attacks. Attackers combine this dataset with other Japan-focused leaks to create comprehensive credential stuffing databases. Each of the 25 email-password pairs will be tested against Japanese banking services, e-commerce platforms, and social media accounts. If even one victim reuses their password, the attacker gains access to far more than what was originally stolen.

Stealer Malware: The Source of Every Record

The JP 3 dataset was generated by infostealer malware running on compromised devices belonging to Japanese users. These infections typically originate from downloading pirated software, clicking phishing links, or installing malicious browser extensions. The malware operates in the background, extracting every saved password from the victim's browser, logging keystrokes during active sessions, and collecting authentication tokens. The stolen data is compiled into structured log files and shared through Telegram channels where threat actors trade regional credential bundles.

Check If Your Credentials Were Exposed

HEROIC's breach intelligence database indexes over 400 billion records from data breaches, stealer logs, and dark web sources. Use the HEROIC breach scanner to check whether your email address or password appears in the JP 3 dump or any other known compromise. Even if this particular leak is small, your credentials may appear in multiple breaches, and HEROIC's comprehensive database will reveal the full scope of your exposure.