Data breach · 2015
The Aternos data breach, explained
Aternos (aternos.org) was breached on December 6, 2015, exposing 1.4 million accounts, passwords included. Here is exactly what leaked, what it means, and the order to fix things in.
1,436,486 accounts · 5 data classes · verified record
The numbers
What the record shows
What leaked
5 kinds of data were exposed
The universal account key. Exposed addresses get targeted with credential-stuffing and phishing that name the breached site to look legitimate.
Rough location and ISP. Low direct harm, useful for correlating accounts.
The one that matters most. Even hashed passwords get cracked at scale, and every account where this password was reused is now reachable.
Ties this account to your other accounts that share the handle, which is how one breach becomes a map of your online life.
What you did on the site, attached to who you are.
In this order
What to do now
Reset the Aternos password first
Use the official forgot-password flow on aternos.org directly, never a link from an email about the breach; breach news is prime phishing bait.
Kill the reuse, which is the real damage
Every account sharing the exposed password is now one automated attempt from gone. This is the tedious part, and it is the part Repass automates: it finds the accounts and runs each site's official reset flow for you.
Scan your email for the rest of your exposure
Run the free breach scan on the address you use most. Aternos is one breach; the median active email address appears in several, and what to fix first depends on the full picture.
Turn on two-factor authentication
A leaked password with a second factor in front of it is a locked door with a stolen key that no longer fits. Prefer an authenticator app over texted codes where the service offers the choice.
Questions
Aternos breach FAQ
Was my Aternos account affected by the breach?
The record covers 1,436,486 accounts. The quick way to check is a breach scan against your own email address, which searches this breach and hundreds of others at once. Repass runs one free on its homepage.
What should I change first after the Aternos breach?
The Aternos password itself, immediately. Then every other account where you used the same or a similar password, because that reuse is what attackers actually exploit.
Is changing my Aternos password enough?
Only if that password lived nowhere else. Credential-stuffing takes leaked email-and-password pairs and tries them on banks, mailboxes and stores at machine speed, so the reused copies matter more than the original. A reused password is a breach of every account that shares it.
Where does this breach data come from?
From the public index maintained by Have I Been Pwned, which verifies breaches before listing them. This page renders the structured record: dates, account count and exposed data classes.
How do I find out what else has leaked about me?
Run a breach scan on your email address. It returns every verified breach that lists the address, which is the honest starting point for deciding what to reset first. Repass then resets the passwords for you, one official flow at a time, and seals each new one in an encrypted vault.
More records
Other major breaches
After the breach
Every reused password, replaced for you.
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