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Data breaches → Ethereum

Was your data in the Ethereum breach?

2016 · ethereum.org · ~16,431 accounts exposedCritical severity · 10/10

Ethereum (ethereum.org) suffered a data breach in 2016 that exposed around 16,431 accounts. If you had an account, some of your personal data may be circulating in leaked databases. The fastest way to know is to check your own email — free, in about 30 seconds, no password required.

What happened

In December 2016, the forum for the public blockchain-based distributed computing platform Ethereum suffered a data breach. The database contained over 16k unique email addresses along with IP addresses, private forum messages and (mostly) bcrypt hashed passwords. Ethereum elected to self-submit the data to HIBP, providing the service with a list of email addresses impacted by the incident.

Breach details sourced from Have I Been Pwned, the industry-standard breach database. Risk analysis by Nullivo.

What was exposed, and why it matters

Not all breaches carry the same risk — what matters is which fields leaked. Here is what the Ethereum breach exposed and what each item actually enables:

Passwords

Attackers replay leaked passwords across other sites (“credential stuffing”). Because most people reuse passwords, one leak often unlocks email, shopping and banking accounts elsewhere.

Private messages

Personal correspondence can be used for blackmail or social engineering, and often contains other sensitive details you have forgotten sharing.

Names and usernames

Links this leak to your other accounts — a reused username lets anyone build a profile of you across platforms.

Email addresses

Puts you on spam and phishing lists, and confirms to attackers that you hold an account with this service — which makes impersonation emails more believable.

IP addresses

Reveals your approximate location and internet provider, which adds credibility to targeted scams.

Also listed in this breach: Email addresses, IP addresses, Passwords, Private messages, Usernames, Website activity.

What to do if you were affected

These steps are ordered for this specific breach — the most urgent action given what leaked comes first.

  1. Passwords: Change this password everywhere you have reused it, starting with your email account — whoever controls your email can reset everything else.
  2. Private messages: Consider what was discussed on this service and whether anything needs changing (shared passwords, personal disclosures).
  3. Names and usernames: Search your usual username to see what else it exposes, and use distinct handles for sensitive accounts.
  4. Email addresses: Treat any message referencing this service with suspicion, and never act on links in unexpected emails.
  5. IP addresses: No direct action needed, but be wary of anyone quoting your location as “proof” of identity.
  6. Check whether your own email appears in this breach — run a free scan to confirm before you spend time on the steps above.

How urgent is this now?

This breach is over 10 years old. Old credentials still cause harm — leaked passwords from a decade ago are still tried against new accounts every day.

Passwords are the reason breach age matters less than people expect. Leaked credentials are compiled into wordlists that get tried against new services for years afterwards, so a password exposed here is unsafe to use anywhere, ever again.

Remember: a breach can't be "un-leaked" — once a database is out, it exists in countless copies. The goal is to make the leaked data useless: change what can be changed, lock down what can't, and remove what has been republished.

Check if your email was exposed.Nullivo's free scan checks your own verified email against known breaches — including Ethereum — in 30 seconds. No password, no signup, and we only ever scan your own email. Run your free scan →

Frequently asked questions

What data was exposed in the Ethereum breach?

The Ethereum breach exposed passwords, private messages, names and usernames, email addresses, ip addresses. Attackers replay leaked passwords across other sites (“credential stuffing”). Because most people reuse passwords, one leak often unlocks email, shopping and banking accounts elsewhere.

How many people were affected by the Ethereum breach?

Around 16,431 accounts were exposed, making it a smaller, more targeted breach.

What should I do if I had a Ethereum account?

Change this password everywhere you have reused it, starting with your email account — whoever controls your email can reset everything else. You can check whether your own email appears in this breach with a free Nullivo scan — no password required.

Breaches that exposed similar data

If the Ethereum breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.

See all breaches we cover →