​Breach Compilation: 773M Unique Emails 2019.0 Data Breach
ObscureIQ Breach Intelligence
Moderate SeverityWebsite / service breach
Collection #1 Credential Compilation: 773 Million Unique Email & Password Pairs Exposed
Aggregated stolen credentials and password pairs.
Verified by ObscureIQ Intelligence
45/100Breach Risk Index
17Data Value
25Market Recency
584dSince Breach
Breach Intelligence Summary
Entity: ​Breach Compilation: 773M Unique Emails · Actor: Unknown (aggregator) · Sources: 3 references
Attack: Scraping / Collection
Profile: Breach Compilation · Aggregated stolen credentials and password pairs · Credential compilation corpus · Global
Timeline: Breach (2019-01-01) · Indexed (Jan 16, 2019) · Year (2019.0)
Exposure: Undisclosed records · 2 fields: Email Address, Password
Status: Compilation
Executive Summary
Collection #1 is a January 2019 compilation of roughly 772.9 million unique email addresses and about 21 million unique passwords, forming over 2.7 billion email/password pairs across some 12,000 files (~87GB). It was assembled from more than 2,000 prior breaches and combolists, with an estimated 140 million new email addresses and 10 million new passwords not previously seen. It is a credential-stuffing resource, not a breach of any one organization.
ObscureIQ assessment: Being in Collection #1 means an email/password combination is circulating for automated login attempts; the mitigation is unique passwords and MFA rather than action against any single company.
Breach Impact
As an aggregated credential-stuffing list, its value to attackers is the sheer breadth of reusable email/password pairs; presence indicates a credential appeared somewhere in the aggregated sources, not that any specific site was breached.
About ​Breach Compilation: 773M Unique Emails
Collection #1 is not a company or a single breach but a large aggregated set of credentials assembled by unknown parties and distributed on hacking forums.
Why They Hold Your Data
Credential compilation corpora aggregate email addresses, usernames, passwords, and login pairs pulled from many separate services into one normalized dataset for reuse and large-scale testing. The core workflow is aggregation, de-duplication, formatting, and redistribution of credentials from multiple prior sources.
Recent Developments
Discovered by researcher Troy Hunt in January 2019, it was, at the time, the single largest set of credentials ever loaded into breach-notification services.
Data Points Exposed
2 verified field types
Email Address
Password Critical
Field names are shown in full for clarity and search visibility. Canonical machine keys are emitted only in this page’s structured data.
Exploitation & Downstream Threats
Threat Activity:High
Primary downstream threats:
Threat vectors:
- Phishing, credential stuffing & account takeover
- Credential stuffing & account takeover
Threat Actor: Unknown (aggregator)
Unknown (aggregator)
Scraping / Collection
Attribution and method are based on available breach intelligence. Reported attack vector: Scraping / Collection.
Recommended Actions
If you believe your information may be included:
Change Reused Passwords
Update this account and anywhere you reused the password; use a manager.
Enable MFA Everywhere
Turn on multi-factor authentication on email first, then financial accounts.
Report & Recover
If you spot misuse, start an official recovery plan and report fraud.
Frequently Asked Questions
What happened in the ​Breach Compilation: 773M Unique Emails breach?▾
Collection #1 is a January 2019 compilation of roughly 772.9 million unique email addresses and about 21 million unique passwords, forming over 2.7 billion email/password pairs across some 12,000 files (~87GB). It was assembled from more than 2,000 prior breaches and combolists, with an estimated…
What data was exposed?▾
Verified fields include Email Address, Password.
What should I do if I was affected?▾
Change reused passwords, enable MFA, and (if identity or financial data is involved) freeze your credit and monitor your accounts.
Sources & References
Every claim on this page is traceable. This breach draws on:
Breach Index
Breach Index
ObscureIQ Intelligence
ObscureIQ proprietary analysis
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