The Piece 855 Hotmail Dump Put 851 Login Pairs Online Last Year

In May 2025, HEROIC analysts identified a combolist titled "Piece - 855 HOTMAIL VALID" uploaded by a Telegram user. The file contained 851 records, each pairing a Hotmail-linked email address with a plaintext password and a source URL, labeled by its creator as containing verified, working logins.

Why This Is Dangerous

The word "valid" in the file name signals that these credentials were tested and confirmed to work before being shared. That means an attacker does not need to guess which entries are real, every record in this file was verified as an active login at the time it was compiled.

What Was Exposed in the Piece 855 Hotmail Leak

• Email addresses
• Plaintext passwords
• Source URLs

Why This Matters

Verified combolists are more dangerous than random leaked data because attackers know the logins work. If any of these 851 Hotmail users reused their password on another site, that same verified credential can be used to break into banking, shopping, or social media accounts too.

How a Combolist Attack Works

Criminals build combolists by collecting stolen credentials and then testing each one against the original service to confirm it still works, labeling the result "valid" before sharing or selling it. Buyers of a verified list can skip straight to using the credentials, making files like this one especially valuable on Telegram and dark web markets.

Check If You Are Affected

Check your email with HEROIC's free breach scanner, which searches more than 400 billion leaked records including this verified Hotmail combolist. If you are listed, change your password immediately, since these credentials were already confirmed to work.