About 183 million unique emails sat in this 2025 stealer-log compilation — malware on devices, not a hack of Synthient the company. Check whether your address is in that file, then treat reused passwords and leftover sessions as the first jobs.
Quick answer — was Synthient Stealer Log Threat Data breached?
No — this page is not a single-company login breach. It is a 2025 aggregation of infostealer logs: about 183 million unique email addresses plus passwords captured on infected devices. A match means your address appeared in that malware-log file. It is not the 1.96-billion-email stuffing row. Check if you were affected.
This catalog row is a 2025 aggregation of infostealer malware logs — not a hack of a company called Synthient, and not the later 1.96-billion-email stuffing compilation. During 2025 Synthient collected “threat data” from places those logs are posted. After normalising and de-duplicating, this lookup lists about 183 million unique email addresses plus passwords. Public analysis of the raw logs describes a typical line as the website that was typed, the email address, and the password. This page follows the catalog fields: emails and passwords.
A stealer-log match is different from a 2013 company dump. The password was often captured as it was used — saved in a browser, typed on a shared PC, or entered on a machine that already had malware. That can make the pair fresher than a hash from a decade-old database. Raw stealer logs commonly also carry session cookies. A stolen cookie can replay a logged-in session and skip a password prompt, including some two-factor setups that only protect the login form. This catalog row does not list cookies as a data type. Treat “log out everywhere” as part of the playbook anyway if you matched.
This catalog’s date is 11 April 2025 — the same window label as the stuffing row, not proof both files are one incident. Public catalogs added this stealer-log row on 21 October 2025, first. The stuffing compilation is a separate slug added 6 November 2025: Synthient Credential Stuffing Threat Data. Public analysis of the October load found about 91 percent of addresses had already appeared in earlier catalogs, with about 16.4 million addresses new to those catalogs. Recycled does not mean harmless. Learn more about what a data breach means for you.
A stealer-log match is different from a 2013 company dump. The password was often captured as it was used — saved in a browser, typed on a shared PC, or entered on a machine that already had malware. That can make the pair fresher than a hash from a decade-old database. Raw stealer logs commonly also carry session cookies. A stolen cookie can replay a logged-in session and skip a password prompt, including some two-factor setups that only protect the login form. This catalog row does not list cookies as a data type. Treat “log out everywhere” as part of the playbook anyway if you matched.
Yes, for the password playbook and for the device-and-session playbook. A match can mean your machine, or a machine you logged into, ran stealer malware at some point. As of 2026 the file is a snapshot of logs that were already being traded. It does not expire. Changing one password without scanning devices or signing out other sessions leaves leftover access on the table.check whether your email was exposed in this breach.
Email addresses — used for phishing attacks and credential stuffing against your other accounts
Passwords — can be used to access your accounts directly or cracked to reveal your actual password
2023–2025
Infostealer malware families circulate via phishing, fake installers, and tainted browser extensions; logs are posted and re-posted on chat channels and forums
2025
Synthient describes ingesting that firehose (Telegram as a large source) and sharing a de-duplicated view so people can look themselves up
11 April 2025
This catalog’s dated label for the stealer-log row — a collection window, shared with the later stuffing row, not a single-company hack date
21 October 2025
Public catalogs add this row at about 183 million unique emails; contemporaneous analysis reports ~91 percent already seen in earlier catalogs and ~16.4 million new addresses
6 November 2025
A separate stuffing compilation is added under Synthient Credential Stuffing Threat Data — different file, different origin
2025–2026
Logs keep circulating; leftover reused passwords and unrevoked sessions from the snapshot still unlock accounts
Yes, for the password playbook and for the device-and-session playbook. A match can mean your machine, or a machine you logged into, ran stealer malware at some point. As of 2026 the file is a snapshot of logs that were already being traded. It does not expire. Changing one password without scanning devices or signing out other sessions leaves leftover access on the table.
A unique password is necessary and not always sufficient here. Sign out other sessions and scan devices. Learn how long stolen data stays dangerous.
An infostealer is malware on a computer or phone. It copies saved passwords, browser data, and often cookies, then ships a “log” to whoever is collecting. Those logs are posted and re-posted on chat channels and forums. Synthient’s public write-up describes ingesting that firehose — Telegram as a large source, plus forums and social posts — so people can look themselves up. That is threat-intelligence collection. It is not Synthient announcing that its own user table was stolen, and it is not EmailLeaked claiming a private tap on hidden markets.
This row is not Synthient Credential Stuffing Threat Data. Stuffing lists are email-and-password pairs bundled from older breaches so a bot can try them on other sites. They usually do not tell you which website the password originally came from. Stealer logs usually do — in the raw file. This email checker still shows a named match, not a live map of every site in the log.
A match is not proof your current laptop is infected today. The capture may have been on an old PC, a family computer, or a machine you already wiped. It is also not a new Gmail-only breach. The same 2025 headlines that flattened stuffing lists into “Gmail hacked” also flatten stealer logs. The playbook is: assume the captured password and any session on that device from that period are burned.
If your address is in the de-duplicated log set, EmailLeaked shows a named Synthient Stealer Log Threat Data match the same way it shows a named company incident. The row is a lookup against industry-standard breach data sources. We do not claim exclusive ownership of Synthient’s corpus, we did not harvest the malware logs, and we do not crawl hidden markets live.
A match is evidence that the address — and typically a password captured on some device — appeared in logs public catalogs loaded in October 2025. It is not a live infection scan. A miss is a snapshot of the records we can search today. We do not keep the address you type into the checker. Hosting logs and a privacy-oriented analytics beacon can still record that the page was visited.
If you want the name decoded in one place, use What is Synthient? Breach names explained. For the response order, use what to do after a data breach and sign out other sessions on email first. To test a reused password without sending the full password, use the password leak checker.
Confirm the match and which Synthient file it is
Run the email check if you need the named incidents in one list. This row is the stealer-log file (emails and passwords from malware logs). The huge combo-list file is Synthient Credential Stuffing Threat Data.
Check this email — freeTreat captured passwords as public and sign out sessions
Change the password on email and on every site that shared it. Use “log out everywhere” or revoke sessions on email, banking, and work. Then check whether that password appears in known leaks without sending the password itself.
Scan devices, then turn on app-based two-factor authentication
Run a current malware scan on machines you still use before you type new passwords into them. An authenticator app is stronger than a text-message code. Cookies in raw stealer logs can skip a password prompt; leftover sessions are the gap.
Follow the after-breach playbook
Use the first-hour and 24-hour lists, then the password playbook plus a device pass. Walk the account security checklist so recovery email, sessions, and leftover logins get a pass.
Open the after-breach playbookCompare how public checkers differ
A second lookup does not change the October 2025 log set. It can show you how different public indexes present the same named dataset.
Read the checker comparisonClose leftover accounts that reused the password
There is no Synthient login to delete. After you change captured passwords and sign out sessions, close leftover site accounts so that old string stops sitting around. That is hygiene, not a way to un-leak the log set.
Browse delete-account guidesBreach pages are built from structured breach records and reviewed for practical risk guidance by EmailLeaked. Risk labels reflect exposed data types and are intended to help readers prioritise action.
Sources
Last updated: September 2026
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