The IONOS SMTPS Breach Happened Aug 8. 995 Accounts Went Public.

What the IONOS SMTPS Combolist Breach Exposed

HEROIC analysts found the IONOS SMTPS combolist after it was shared by a Telegram user on 08-Aug-2026. The file contains 995 records, each combining an email address, a plaintext password, and the URL the login was tied to.

Why This Is Dangerous

A combolist is a ready-to-use list of email and password pairs, compiled by attackers from older breaches and leaks. Anyone who gets this file can immediately try each pair against other websites, no hacking skill needed, just automated software doing the work.

What Was Exposed

• Email addresses
• Plaintext passwords
• URLs linked to each login

Why This Matters

Combolists like this one are the fuel behind credential stuffing attacks, where criminals feed thousands of email and password pairs into login pages across the internet to see what still works. If any of these 995 passwords were reused elsewhere, the accounts tied to them are exposed to account takeover, identity theft, and financial fraud.

How This Combolist Works

Unlike malware that steals data directly from a device, a combolist is usually assembled from older breaches, leaked databases, and previous stealer logs, then cleaned up and organized into simple email and password pairs. The IONOS SMTPS combolist follows this pattern, packaging working credentials with their matching URLs so attackers can plug them straight into automated login tools.

Check If You Are Affected

Do not wait to find out the hard way. HEROIC's free breach scanner checks your email against more than 400 billion leaked records, including the IONOS SMTPS combolist, so you can see your exposure and update any reused passwords immediately.