Synthient Credential Stuffing Threat Data
What was exposed
Email addressesPasswords
What to do if you were affected
- Change your password for this account, and anywhere you reused it. Turn on two-factor authentication.
- Expect more phishing and spam at this address. Treat messages that reference this company with extra caution.
Details
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.
Frequently asked questions
What is the Synthient Credential Stuffing Threat Data data 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,...
When did the data breach happen?
This data breach occurred around April 2025.
How many accounts were affected?
Around 1,957,476,021 accounts were affected.
What information was exposed?
Exposed data included Email addresses and Passwords.
What should I do if I was affected?
Change your password for this account, and anywhere you reused it. Turn on two-factor authentication. Expect more phishing and spam at this address. Treat messages that reference this company with extra caution.
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