critical severity April 11, 2025 · 3 min read

Synthient Credential Stuffing Threat Data Data Breach (2025)

If you are a customer of Synthient, here’s what’s now in circulation.

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 expo

Synthient Credential Stuffing Threat Data Data Breach (2025)

On April 11, 2025, threat-intelligence firm Synthient disclosed that it had collected 1.957 billion unique email addresses and 1.3 billion unique passwords exposed in credential-stuffing lists circulating across malicious internet sources. The data, drawn from earlier breaches and now integrated into Have I Been Pwned, affects anyone who has reused the same email-and-password combination across multiple services.

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What's Publicly Reported from Reporting

Public reporting indicates Synthient spent much of 2025 aggregating credential-stuffing lists that attackers compile from previous data breaches. These lists contained email addresses and passwords belonging to nearly two billion distinct accounts. The firm worked with Have I Been Pwned to make the passwords searchable in its Pwned Passwords database and to alert affected individuals. No new systems were breached by Synthient itself; the company acted as an aggregator of already-leaked material found in criminal forums and repositories.

Why This Matters for You and Your Family

If any of your accounts appear in these lists, attackers already possess working username-and-password pairs that can be tested against banks, email providers, social networks, shopping sites, and school portals. Because families often share similar password patterns or reuse credentials across adult and children’s accounts, one exposed email can place every household member at risk. The breach volume — nearly two billion records — means the odds that you or someone you live with is included are uncomfortably high.

The Doxxing and Identity-Chain Implications

Credential leaks like this one rarely stop at login attempts. Once attackers gain access to even one account, they harvest linked phone numbers, alternate emails, and personal details that allow them to map additional online handles back to real-world identities. This chaining process can expose family relationships, children’s gaming usernames, home addresses, and photos. What begins as an old password from an unrelated breach can cascade into full doxxing within hours if the same credentials unlock a primary email or social-media account.

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What the free scan actually returns

Sample resultyou@email.comIllustrative — not a real person

Found on people-search siteswe remove these

These listings are live, public, and legal to remove — and removing them is what we do.

value redacted in this sampleage, relatives, address historySpokeo

value redacted in this samplephone, household, property recordsBeenVerified

value redacted in this sample582 companies checked

Found in breach recordsverifiedreported — unverified

Each record is labeled: confirmed breach data, or an attacker’s claim no one has verified.

verifiedvalue redacted in this samplepassword + phone · 2024telecom breach

unverifiedvalue redacted in this sampleclaimed in ransomware listing · 2026leak-site claim

Leaked data cannot be deleted from the internet — anyone claiming otherwise is lying. Broker listings can be removed. We do the second, and show you exactly what to fix from the first.

Report details & sourcing

Severity Critical contact details only, none of them permanent

Disclosed April 11, 2025

Last reviewed July 22, 2026

Affected 1957.5M

Data exposed Email addressesPasswords

By GalaxyWarden Threat Research · Editorial & sourcing standards

Editorial & sourcing policy

GalaxyWarden is a breach-monitoring service and news aggregator. We do not exfiltrate, host, purchase, or redistribute stolen data. Breach information is compiled from publicly accessible sources and threat-intelligence platforms, and is reported as claims attributed to their source. We promptly correct or remove material shown to be inaccurate — see our content & takedown policy or write to support@galaxywarden.com.

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