MyRecon OSINTSynthient Stealer Log Threat Data
On 11 April 2025, Synthient Stealer Log Threat Data was breached. 182,962,095 accounts were exposed, including email addresses, passwords. MyRecon rates it 83/100, critical. That is roughly everyone in Russia.
183 million unique addresses, harvested by malware from individual people's own machines, gathered into one set in the course of a single year. The volume is the finding. Endpoint infection is not a rare misfortune that befalls careless people, at this scale it is a background condition of using a computer.
What separates this from a leaked database is where the data was standing when it was taken. A breach exposes what a company stored about you. A stealer log exposes what you typed, into services that were never breached, including ones whose security is genuinely good, along with whatever the browser had saved on your behalf. The browser's password store is usually the first thing collected, because it is one file and anything running as you can decrypt it.
So the response starts with the machine and not the accounts. Cracked software and convincing installers for legitimate tools are how most of these infections arrive, which is why the population in these files skews towards people who thought they were being resourceful rather than reckless. If an address of yours turns up in a set like this, treat everything entered on that device as known, clean or rebuild it first, and only then rotate credentials, beginning with the mailbox that can reset all the others.
What happened
During 2025, Synthient aggregated billions of records of "threat data" from various internet sources. The data contained 183M unique email addresses alongside the websites they were entered into and the passwords used. After normalising and deduplicating the data, 183 million unique email addresses remained, each linked to the website where the credentials were captured, and the password used. This dataset is now searchable in HIBP by email address, password, domain, and the site on which the credentials were entered.
Breach description from Have I Been Pwned, used under a CC BY 4.0 licence.
Who was behind it
No party has been publicly confirmed as responsible, and this page will not name one. Most breaches are never formally attributed: data surfaces on a forum or inside a combined dump long after the intrusion, and the trail back to a specific actor is rarely made public. Where a group has claimed responsibility it is usually named in the account above, that claim is theirs, not a finding of ours. These records came from information-stealing malware on victims' own machines rather than from one company's servers, so the exposure follows the person, not the site.
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 Stealer Log Threat Data breach?
Enter it in the box at the top of this page. MyRecon checks it against this breach and every other one on record, and the address is never stored.
What data was leaked in the Synthient Stealer Log 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 21 October 2025, a gap of 194 days during which the data was already out.
Is the Synthient Stealer Log 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?
182,962,095 accounts. That is roughly everyone in Russia. 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.