The 3.7K JP MOON Combolist Leaked 3,683 Passwords in January

What HEROIC Analysts Found

The combolist known as 3.7K JP MOON was leaked on January 11, 2026, but it only came to HEROIC analysts' attention after a Telegram user uploaded it more recently. The file contains 3,683 records pairing email addresses with plaintext passwords and the URLs of the accounts they belong to.

Why the Delay Makes This Worse

Months passed between when 3.7K JP MOON was first leaked and when it started circulating more widely. That gap matters: passwords sitting quietly in a file for months are just as usable as ones stolen yesterday, and anyone who has not changed their password since January is still exposed. The longer a leak like this goes unnoticed, the more time attackers have had to use it before the people affected ever find out.

What Was Exposed

• Email addresses
• Plaintext passwords
• URLs linking each credential pair to its original account

Why This Matters

A combolist that has been quietly available since January could already have been used for credential stuffing, account takeover, or fraud, well before anyone flagged it publicly. If your password hasn't changed since then and you reuse it elsewhere, your risk has been sitting there the whole time.

How Combolists Work

A combolist bundles email or username and password pairs, sourced from stealer logs, old breaches, or phishing, into one list that criminals can run against many sites at once. Files like 3.7K JP MOON often resurface and get redistributed on Telegram long after they were first put together, which is exactly why timing matters.

Check If You Are Affected

Don't wait for another leak like this to resurface before you find out. HEROIC's free breach scanner checks your email against more than 400 billion records, including combolists that leaked months ago, and tells you immediately if a password change is overdue.