Aternos
HIGH RISKData breach — December 2015
In December 2015, the service for creating and running free Minecraft servers known as Aternos suffered a data breach that impacted 1.4 million subscribers. The data included usernames, email and IP addresses and hashed passwords.
search Check if you were affected — freeData exposed in this breach
What happened in the Aternos data breach?
In December 2015, the service for creating and running free Minecraft servers known as Aternos suffered a data breach that impacted 1.4 million subscribers. The data included usernames, email and IP addresses and hashed passwords.
The exposed data included 5 types of personal information. Because passwords were exposed, users who reused their password on other sites are at particular risk. Learn more about what a data breach means for you.
Quick answer — was Aternos hacked?
Yes. Aternos was breached in December 2015. The breach exposed 1,436,486 records including email addresses, ip addresses, passwords. This breach has been independently verified. If your email was involved, your data may still be at risk today. Check if you were affected.
Why was the Aternos breach so dangerous?
The Aternos breach exposed 1,436,486 records — that is 1.4M people whose personal data is now circulating on the dark web. The combination of email addresses, ip addresses, passwords makes this a high-risk breach that requires immediate action.
Because passwords were exposed, attackers can use credential stuffing to automatically test your Aternos password against hundreds of other websites. If you reused your password anywhere, those accounts are now at risk. Read more about what happens to your data after a breach.
Don't wait to find out — check if your email was exposed in this breach now.
What data was stolen in the Aternos breach?
Email addresses — used for phishing attacks and credential stuffing against your other accounts
IP addresses — combined with other data, used for identity theft and physical fraud
Passwords — can be used to access your accounts directly or cracked to reveal your actual password
Usernames — used to build profiles and target you with personalised scams
Website activity — may be combined with other breach data to build a profile for targeted attacks
Is the Aternos breach still dangerous in 2026?
Yes. Stolen data from the Aternos breach remains dangerous years after the incident. Research shows that over 65% of stolen credentials from older breaches have never been changed by the account holders. Attackers routinely compile data from multiple breaches to build complete profiles, and credentials from 2015 are still actively used in credential stuffing attacks today.
Personal information like email addresses, phone numbers, and dates of birth never expire. Even if you changed your Aternos password, the other exposed data can be combined with information from other breaches to target you. Learn more about how long stolen data stays dangerous.
Frequently asked about the Aternos breach
Approximately 1,436,486 user records were exposed in the Aternos breach in December 2015.
Yes. Leaked credentials are actively used in credential stuffing attacks years after a breach. If you reused your Aternos password elsewhere and haven't changed it, those accounts remain at risk today.
Enter your email in the free checker on EmailLeaked. We scan 12 billion+ breach records including the full Aternos dataset and tell you instantly whether your email was exposed and what data was taken.
Change your Aternos password immediately, change any other account where you used the same password, enable two-factor authentication on all important accounts, and monitor for phishing emails over the next 90 days.
Who was affected by the Aternos breach?
The Aternos data breach affected approximately 1,436,486 users who had accounts with the service. While not the largest breach on record, it still represents a significant number of compromised accounts in our database of 970+ known breaches.
If you ever created an account with Aternos or used their services, your data may have been included in this breach. Check your email now to find out. You can also read our guide on what to do immediately after a data breach.
If your email was in the Aternos breach
Change your Aternos password immediately
Go to Aternos and change your password right now. Use a strong, unique password that you have never used anywhere else.
Change any account sharing that password
If you used the same password on other sites, change it on every one of them. Attackers test stolen credentials on hundreds of popular sites within hours.
Enable two-factor authentication
Turn on 2FA on Aternos and every important account. Even if your password is known, attackers cannot get in without the second factor.
Check your other accounts for this breach
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