The Gmail 499.3K Combolist Means Someone Could Access Your Inbox

HEROIC analysts identified a combolist labeled "Gmail 499.3K" circulating on a Telegram channel in February 2023. The file paired 479,207 email addresses with plaintext passwords and the URLs of the sites those logins belong to, the standard format attackers use to automate login attempts across the web.

Why the Gmail 499.3K Combolist Is Dangerous

Picture a stranger sitting down at your inbox with your exact password already typed in. That is effectively what this combolist hands to anyone who downloads it. The passwords were stored in plaintext, so there is no cracking involved, an attacker just copies an email and password pair and tries logging in. With nearly half a million entries in this one file, it is built to be fed into automated tools that attempt logins by the thousands per minute.

What Was Exposed

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

Why This Matters

Anyone whose email and password appear in the Gmail 499.3K file faces a real risk of credential stuffing, where automated tools feed leaked logins into hundreds of websites at once looking for a match. Because these are inbox credentials, a successful login can let an attacker read private messages, reset passwords on other accounts, and impersonate the victim in emails to contacts. If the password here has ever been reused on another account, that account is exposed too.

How Combolists Like This One Are Built

Combolists are compiled by merging credentials pulled from older breaches, phishing kits, and malware logs into a single searchable file, then formatted as email:password or email:password:URL so they can be fed straight into automated login tools. They are traded and sold cheaply on Telegram and dark web forums because they let low-skill attackers run large-scale login attempts with almost no technical effort. A file's age does not make it safe. Old combolists still work against anyone who has not changed the password since.

Check If You Are Affected

You do not have to guess whether your information is sitting in a dump like this one. HEROIC's free breach scanner checks your email address against more than 400 billion leaked records pulled from combolists, stealer logs, and dark web marketplaces. Run a free scan, and if a match turns up, change that password everywhere else you have used it.