1.1KK UHQ Yahoo USA Best NNL Leak Exposed 1.1 Million US Accounts

1.1KK UHQ Yahoo USA Best NNL Leak: 1,099,265 Accounts Exposed

HEROIC analysts identified a large combolist named "1.1KK UHQ Yahoo USA Best NNL" that was uploaded to a Telegram channel on 10 December 2022. The file contains 1,099,265 records tied to United States based Yahoo accounts, pairing email addresses with plaintext passwords and associated URLs, one of the larger combolists HEROIC has tracked from Telegram distribution.

Why This Is Dangerous

Every password in this file is stored in plaintext, meaning an attacker does not need to crack or guess anything before trying it. With over a million email and password pairs in one file, criminals can run automated login attempts against Yahoo and other popular sites at scale, and any victim who reused their password elsewhere is exposed on those accounts too.

What Was Exposed

• Email addresses
• Plaintext passwords
• Associated URLs

Why This Matters

A combolist of this size is exactly the kind of resource that fuels large-scale credential stuffing campaigns, where automated tools test each stolen email and password pair against dozens of websites in seconds. Because many people still reuse passwords across email, banking, and social media accounts, a single leaked Yahoo password can open the door to identity theft or financial fraud far beyond the original account.

How a Combolist Leak Works

A combolist compiles login credentials, an email or username paired with a password, gathered from earlier breaches, phishing campaigns, or malware infections and packaged for resale or free distribution. Telegram has become a common venue for sharing these files because uploads are quick, low cost, and difficult for platforms to police. This particular combolist circulated for roughly three years before being identified, giving attackers a long window to exploit the exposed credentials.

Check If You Are Affected

If you have a Yahoo account, especially one tied to the United States, or if you have ever reused a password across multiple sites, it is worth checking whether your information appears in this leak. HEROIC's free breach scanner searches a database of more than 400 billion leaked records to tell you instantly if your email has been exposed, so you can secure your accounts before someone else does.