The Synthient Stealer Log dataset — disclosed in 2025 — contains approximately 183 million records sourced from stealer malware logs harvested from infected devices worldwide. Unlike credential-stuffing lists compiled from historical breaches, stealer logs capture usernames, passwords, session cookies, and form data taken directly from victims' machines in real time by malicious software. Synthient processed and disclosed the dataset to allow users to discover whether their credentials appeared.
Quick answer — was Synthient Stealer Log Threat Data breached?
Yes. Synthient Stealer Log Threat Data was breached in April 2025, exposing 182,962,095 records including email addresses, passwords. This breach has been independently verified. If your email was involved, your data may still be at risk today. Check if you were affected.
What happened in the Synthient Stealer Log Threat Data data breach?
The Synthient Stealer Log dataset — disclosed in 2025 — contains approximately 183 million records sourced from stealer malware logs harvested from infected devices worldwide. Unlike credential-stuffing lists compiled from historical breaches, stealer logs capture usernames, passwords, session cookies, and form data taken directly from victims' machines in real time by malicious software. Synthient processed and disclosed the dataset to allow users to discover whether their credentials appeared.
Stealer-log credentials are often newly valid — captured from active sessions rather than old databases — making them significantly more dangerous than typical breach data. Because the data includes session cookies, attackers may impersonate an already-authenticated session and bypass two-factor authentication entirely without knowing the account password. Business email accounts, cloud services, and internal corporate systems are the primary targets for stealer-log-derived access.
Information stealer malware — distributed through phishing emails, malicious software installers, and compromised browser extensions — has become the dominant method for fresh credential harvesting in 2024–2025, surpassing traditional database breaches in the operational value of the data it produces.
Learn more about what a data breach means for you.
Why was the Synthient Stealer Log Threat Data breach so dangerous?
Stealer-log credentials are often newly valid — captured from active sessions rather than old databases — making them significantly more dangerous than typical breach data. Because the data includes session cookies, attackers may impersonate an already-authenticated session and bypass two-factor authentication entirely without knowing the account password. Business email accounts, cloud services, and internal corporate systems are the primary targets for stealer-log-derived access.
What data was stolen in the Synthient Stealer Log Threat Data breach?
Email addresses Passwords
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
Timeline of the Synthient Stealer Log Threat Data breach
2023–2025
Stealer malware (Redline, Vidar, Raccoon, and variants) deployed globally via phishing and trojanised installers
2025
Synthient analyses and aggregates approximately 183 million stealer-log records from collected samples
2025
Dataset disclosed to the security community; added to public breach database
Is the Synthient Stealer Log Threat Data breach still dangerous in 2026?
Yes. Stolen data from the Synthient Stealer Log Threat Data breach remains dangerous years after the incident. Attackers routinely compile data from multiple breaches to build complete profiles, and credentials from 2025 are still actively used in automated attacks today.
Personal information like email addresses, phone numbers, and dates of birth does not expire. Even if you changed your Synthient Stealer Log Threat Data password, the other exposed data can be combined with information from other breaches to target you.
Learn how long stolen data stays dangerous.
What to do if your email was in the Synthient Stealer Log Threat Data breach
1
Change your Synthient Stealer Log Threat Data password immediately
Log into Synthient Stealer Log Threat Data and change your password to something strong and unique — one you have never used anywhere else.
2
Change any account sharing that password
If you reused this password elsewhere, change it on every affected account. Attackers test stolen credentials against hundreds of popular sites within hours.
3
Enable two-factor authentication
Turn on 2FA on Synthient Stealer Log Threat Data and every important account. Even if your password is known, attackers cannot access the account without the second factor.
4
Check your other accounts for this breach
Run a full email scan to see every breach your address appears in — not just this one.
Frequently asked about the Synthient Stealer Log Threat Data breach
What is stealer malware and how does it work?
Stealer malware (also called information stealers) is software secretly installed on a victim's device that copies saved passwords, browser cookies, form-fill data, and cryptocurrency wallet files, then sends them to an attacker. It typically arrives via phishing emails, fake software downloads, or compromised browser extensions.
Is my computer currently infected if I appear in this dataset?
Not necessarily — the infection that produced your log entry may have been removed or occurred on a device you no longer use. However, any credentials captured at the time of infection should be treated as compromised. Scan your current devices with an updated security tool and rotate all exposed credentials.
Why are stealer logs more dangerous than regular breach data?
Traditional breach data is often months or years old by the time it is disclosed. Stealer logs are captured in real time, meaning the passwords and session cookies they contain are often still valid when attackers use them. Session cookies in particular can bypass two-factor authentication.
What should I do if my credentials appeared in a stealer-log dataset?
Change all exposed passwords immediately. Log out of all active sessions on your most sensitive accounts (email, banking, work systems). Enable two-factor authentication using an authenticator app rather than SMS. If you believe your device was infected, run a full antivirus scan before re-entering any credentials.
How this breach page is reviewed
Breach 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.