The 500K Yahoo Combolist: 483,391 Stolen Login Credentials Leaked

500K Yahoos Combolist: 483,391 Records Traced to Telegram

HEROIC analysts traced a combolist advertised as "500k yahoos" to a Telegram upload from March 2023. Verification showed the file actually contained 483,391 records, each pairing a Yahoo email address with a plaintext password and the URL the credential was captured from.

Why This Is Dangerous

Because the passwords in this file sit in plaintext, anyone who downloads it can read every credential instantly, with no cracking required. Paired with the matching URL, an attacker can move straight from opening the file to attempting a login on nearly half a million Yahoo accounts, one of the largest single leaks HEROIC has tracked from this channel.

What Was Exposed

• Email Addresses
• Plaintext Passwords
• URLs

Why This Matters

A Yahoo inbox is frequently used as a password recovery address for banking, shopping, and social media accounts, so gaining access to one can quickly cascade into other compromises. With 483,391 records available, attackers can run large-scale credential stuffing campaigns, and anyone who reused their Yahoo password elsewhere faces a real risk of account takeover, identity theft, or financial fraud.

How Combolists Work

A combolist is a plain text file that pairs stolen usernames or email addresses with matching passwords, usually gathered from earlier breaches, phishing campaigns, or malware and then bundled together for resale or free distribution. A batch this large is typically compiled from multiple smaller sources over time and marketed by its size, exactly how it was advertised here, before being shared widely on Telegram.

Check If You Are Affected

If you have or have ever had a Yahoo account, it is worth checking whether your information is part of this leak. HEROIC's free breach scanner searches more than 400 billion leaked records, including combolists like this one, so you can find out quickly and change any exposed password before someone else uses it.