Breach Database / Synthient Credential Stuffing Threat Data
Yes — Synthient Credential Stuffing Threat Data was breached.
- 2 billion accounts affected
- Breach occurred 2025-04-11
- Verified entry in the Have I Been Pwned catalog
What happened
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.
What data was exposed
- Email addresses
- Passwords
What to do right now
- Change your password for this service now. And change it anywhere you reused the same password — attackers try leaked passwords on other sites within hours ("credential stuffing").
- Turn on two-factor authentication. Even a leaked password is useless against an account protected by a second factor. Prefer an authenticator app over SMS.
- Expect convincing phishing emails. Attackers use breached details to write personalized emails. Be suspicious of any message referencing this service.
- Check your other accounts on Have I Been Pwned. Your email address may appear in other breaches you don't know about yet.
- Monitor the apps you use going forward. Clearly watches the breach record for the companies behind your apps and alerts you the moment one appears.
Breach data from Have I Been Pwned. Listing here means the service appears in the public breach record — not that your personal data was affected.