Collection #1
What Happened
In January 2019, a large collection of credential stuffing lists (combinations of email addresses and passwords used to hijack accounts on other services) was discovered being distributed on a popular hacking forum. The data contained almost 2.7 billion records including 773 million unique email addresses alongside passwords those addresses had used on other breached services. Full details on the incident and how to search the breached passwords are provided in the blog post The 773 Million Record "Collection #1" Data Breach.
Compromised Data
Recommended Actions
Change Your Password
If you haven't changed your password on this service since the breach, do so immediately.
Enable Two-Factor Authentication
If 2FA is supported, add an extra layer of security to your account.
Check Other Accounts
If you used the same password elsewhere, change those too.
Monitor for Suspicious Activity
Watch for unusual login attempts, spam and phishing emails.
Breach Overview
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Affected Accounts:
772.9 million
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Breach Occurred:
January 2019
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Added to HIBP:
16 Jan 2019
Breach Classification
Some breaches may be flagged as "unverified". In these cases, whilst there is legitimate data within the alleged breach, it may not have been possible to establish legitimacy beyond reasonable doubt.
Unverified breaches are still included in the system because regardless of their legitimacy, they still contain personal information about individuals who want to understand their exposure on the web.
Recommended Actions
Change Your Password
If you haven't changed your Collection #1 password since 2019, do so immediately.
Enable Two-Factor Authentication
Add an extra layer of security to your account.
Check Other Accounts
If you used the same password elsewhere, change those too.
Monitor for Suspicious Activity
Watch for unusual login attempts or messages from your account.
