1,443 Corporate Emails Leaked in Japan Corp-Others-Pro Mails Sample

1,443 Records Exposed in a Japan-Targeted Corporate Mail Sample

HEROIC analysts identified a combolist labeled "JAPAN CORP-OTHERS-PRO MAILS TEST SAMPLE," uploaded by a Telegram user on 22 February 2026. The file contains 1,443 records pairing email addresses with plaintext passwords, along with the URLs each credential pair was tied to.

Why This Is Dangerous

The listing's own label points to corporate mail accounts, and being marketed as a "test sample" often signals that a larger dataset exists behind it. Because the passwords are stored in plaintext and paired with URLs, an attacker can log directly into these accounts without cracking anything, and a working corporate inbox can be a gateway into an entire organization.

What Was Exposed

• Email addresses
• Plaintext passwords
• URLs tied to each credential pair

Why This Matters

Corporate email credentials are especially valuable to attackers because reused passwords can unlock other business systems, cloud storage, or financial tools tied to the same account. This kind of exposure feeds directly into credential stuffing and business email compromise attempts, and once inside, attackers can pivot toward identity theft or financial fraud using the access they gain.

How Combolists Work

A combolist bundles email and password pairs, often collected from breaches or malware and labeled by the target audience, as this one was tagged for Japan-based corporate mail accounts. Sellers frequently release a small "test sample" on channels like Telegram to prove the data works before offering the full list, letting buyers verify quality before a larger purchase.

Check If You Are Affected

With 1,443 records from this sample already circulating, it is worth checking your exposure now. HEROIC's free breach scanner searches more than 400 billion leaked records, including combolists like this one, so you can confirm whether your email address was exposed and update your password before someone else uses it.