MyRecon OSINTNational Public Data
On 9 April 2024, National Public Data was breached. 133,957,569 accounts were exposed, including dates of birth, email addresses, genders. MyRecon rates it 77/100, severe. That is roughly everyone in Japan.
The story behind the breach
In April 2024, a large trove of data made headlines as having exposed "3 billion people" due to a breach of the National Public Data background check service . The initial corpus of data released in the breach contained billions of rows of personal information, including US social security numbers.
Further partial data sets were later released including extensive personal information and 134M unique email addresses, although the origin and accuracy of the data remains in question. This breach has been flagged as "unverified" and a full description of the incident is in the link above.
Breach description from Have I Been Pwned, used under a CC BY 4.0 licence.
How did it happen?
The published account does not explain the exact way the data was obtained.
What was the motive?
The published account does not establish the motive. We cannot tell what the attackers intended from the exposed data alone.
Reported demands or attempts to sell data describe what happened, rather than prove every attacker's intention.
What was the outcome?
133,957,569 accounts are listed in this breach. This is a count of accounts, not necessarily individual people.
The reported exposed data includes Dates of birth, Email addresses, Genders, Government issued IDs, Names, Phone numbers, Physical addresses.
What was exposed, and why it matters
- Dates of birthOne of the three things call centres ask to verify identity, and it never changes.
- Email addressesThe address becomes a confirmed, active target, expect more phishing, better aimed.
- GendersSmall on its own; useful to anyone assembling a fuller profile.
- Government issued IDsPassport and licence numbers are used to prove identity to banks and telecoms, and they are effectively permanent.
- NamesTurns an anonymous address into an identified person, which is what makes targeted phishing possible.
- Phone numbersEnables SIM-swap attacks against SMS two-factor codes, and puts the number on scam-call lists indefinitely.
- Physical addressesWhere someone actually lives. Combined with a name this moves the risk off the internet.
What to do if you were in it
- Move two-factor authentication off SMS and onto an authenticator app, which a SIM swap cannot intercept.
- Consider a credit freeze. A government identifier cannot be changed, so limiting what can be opened in your name is the only real control.
- Be sceptical of post and callers who already know your address, knowing it is no longer evidence of anything.
- Expect better-aimed phishing. A message that already knows your name and where you have an account is the whole point of a breach like this.
Questions people ask about this breach
Was my email address in the National Public Data breach?
Use the email box on this page. The result applies only to this incident. If the provider does not cover this breach, we say so. A missing match does not prove you were unaffected.
What data was leaked in the National Public Data breach?
dates of birth, email addresses, genders, government issued ids, names, phone numbers, physical addresses. Each one is explained above, along with what it means for the person it belongs to.
When did it happen, and when did it become public?
The breach is dated 9 April 2024. It was published to Have I Been Pwned on 13 August 2024, a gap of 127 days during which the data was already out.
Is the National Public Data breach real?
It is listed as unverified. The data exists and has been indexed, but it has not been confirmed against the named source, so treat the origin as unproven.
How many people were affected?
133,957,569 accounts. That is roughly everyone in Japan. That is accounts rather than people, one person often has several.
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Three kinds of content appear on this page and they are kept apart deliberately. The breach description is quoted from Have I Been Pwned under its licence. The severity score, the field-by-field explanation and the advice are computed from the record itself, every sentence derives from a number or a flag in it, which is what stops the analysis drifting from the evidence. Anything under the "MyRecon's take" byline is editorial: our reading of this breach, presented as opinion rather than as a finding.