MyRecon OSINTSynthient Credential Stuffing Threat Data
On 11 April 2025, Synthient Credential Stuffing Threat Data was breached. 1,957,476,021 accounts were exposed, including email addresses, passwords. MyRecon rates it 84/100, critical. That is roughly everyone in India.
This entry is not a company being breached. It is an aggregate, two billion addresses collected from credential-stuffing lists that were already circulating, built from other people's breaches and from information-stealing malware on victims' own machines. Nobody was attacked to create it.
Which means finding yourself here answers a different question than usual. It does not tell you which service failed. It tells you that a password of yours, from somewhere, at some point, is in the pool that gets tried automatically against banks, mailboxes and retailers. That is worse in one specific way: there is no single site to go and fix.
The part people miss is the stealer-log component. Credentials harvested by malware come from a compromised device, not a compromised website, so they can include passwords that were never leaked by any company, typed into sites that have never been breached at all. If that is the source, changing one password is not enough; the machine that captured it needs to be cleaned first, or the replacement joins the same list.
The useful response is boringly structural. Unique passwords everywhere, generated and stored in a manager, and two-factor authentication on anything that can reset something else. Aggregates like this one are the reason credential stuffing works at all, and they are the reason it stops working against people who never reuse.
The story behind the breach
During 2025, the threat-intelligence firm Synthient aggregated 2 billion unique email addresses disclosed in credential-stuffing lists found across multiple malicious internet sources . Comprised of email addresses and passwords from previous data breaches, these lists are used by attackers to compromise other, unrelated accounts of victims who have reused their passwords. The data also included 1.3 billion unique passwords, which are now searchable in Pwned Passwords.
Working to turn breached data into awareness, Synthient partnered with HIBP to help victims of cybercrime understand their exposure.
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?
1,957,476,021 accounts are listed in this breach. This is a count of accounts, not necessarily individual people.
The reported exposed data includes Email addresses, Passwords.
What was exposed, and why it matters
- Email addressesThe address becomes a confirmed, active target, expect more phishing, better aimed.
- PasswordsAnyone reusing this password elsewhere has those accounts exposed too, credential stuffing is automated and tries them all within days.
What to do if you were in it
- Change this password anywhere you reused it, starting with your email account, that is the one that can reset all the others.
- 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 Synthient Credential Stuffing Threat 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 Synthient Credential Stuffing Threat Data breach?
email addresses, passwords. 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 11 April 2025. It was published to Have I Been Pwned on 6 November 2025, a gap of 209 days during which the data was already out.
Is the Synthient Credential Stuffing Threat Data breach real?
Yes. Have I Been Pwned lists it as verified, meaning the data was checked against the source rather than taken on trust.
How many people were affected?
1,957,476,021 accounts. That is roughly everyone in India. 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.