Exploit.In 2016 Data Breach
ObscureIQ Breach Intelligence
High SeverityCredential combolist
Exploit.In Cybercrime Credential Compilation (2016): 591 Million Email & Password Pairs Distributed via Criminal Forum
Cybercrime credential distribution forum
Verified by ObscureIQ Intelligence
62/100Breach Risk Index
25Data Value
25Market Recency
512dSince Breach
Breach Intelligence Summary
Entity: Exploit.In · Actor: Unknown (compilation distributor; original sources various prior breaches) · Sources: 11 references
Attack: Credential Stuffing
Profile: Threat Actor Infrastructure · Cybercrime forum and credential distribution · Criminal forum and combo list distribution source · Global
Timeline: Breach (2016-10-13) · Indexed (Dec 01, 2024) · Year (2016)
Exposure: 591.3M records · 2 fields: Email Address, Password
Status: Confirmed
Executive Summary
The Exploit.In combo list is a large-scale aggregated credential compilation that surfaced publicly in approximately October 2016 through distribution on the Russian-language Exploit.in cybercrime forum. The compilation aggregates email addresses and passwords from numerous prior unrelated breaches across many online services, packaged into a single file format optimized for credential-stuffing attacks. The dataset was indexed by Have I Been Pwned in May 2017 and redistributed by DataBreach.com on December 1, 2024. The compilation contained approximately 593,427,119 unique email addresses based on records indexed by Have I Been Pwned, with the total number of email-and-password pairs exceeding 800 million because many email addresses appeared multiple times paired with different passwords (reflecting the same user's password reuse or distinct passwords across multiple compromised services). The compilation was distributed as approximately 24 gigabytes of plaintext-format data. Compromised fields were limited to email addresses and passwords, with passwords typically appearing in plaintext format reflecting either the original storage format on the source breaches or post-breach hash recovery by the compilation's curators. The original sources of the compiled credentials were various prior breaches across many years of online-service compromises, with the specific source breaches generally not individually attributable from the compilation file format. For affected users, the practical risk profile is moderate to severe and varies depending on the user's password practices and the staleness of the compiled credentials. The compilation's primary harm is to support credential-stuffing attacks against other online services where the user reused the same email-and-password combination, with attackers using automated tools to test the leaked combinations against major email, financial, social media, and e-commerce platforms. Users whose Exploit.In-listed passwords remain in active use on other services face account-takeover risk. Users who have rotated passwords since 2016 face minimal direct risk from the compilation, although the email addresses themselves may remain useful for targeted phishing and spam. Affected users should ensure that any password that may have been included in the Exploit.In compilation is no longer in use on any current accounts, enable two-factor authentication on important accounts including email, financial services, and social media, and use a password manager to ensure that each online service has a unique password. The persistence of the Exploit.In compilation in cybercrime trading communities means that affected credentials may continue to be tested against new platforms and emerging services indefinitely.
ObscureIQ assessment: Exposure enables criminal-network mapping, retaliation, blackmail, and law-enforcement targeting. Credential-distribution context also reveals actors involved in large-scale access abuse.
Breach Impact
n/a (compilation/aggregated combolist; not a breach of an identifiable victim entity).
About Exploit.In
The 'Exploit.In' combo list is a large-scale aggregated credential compilation that was distributed on the Russian-language Exploit.in cybercrime forum in late 2016 and subsequently broadly circulated within the cybercrime ecosystem. The combo list is not a breach of any single entity; rather, it is a compilation of email addresses and passwords aggregated from numerous prior unrelated breaches across many online services, packaged into a single file format optimized for credential-stuffing attacks. Exploit.in (the Russian-language cybercrime forum where the compilation was first distributed) is a separate entity from the affected user population, who are largely individuals whose credentials had been previously stolen from various unrelated online services. As an aggregated combolist, the dataset reflects the broader credential-trading ecosystem rather than a single source-of-compromise event.
Why They Hold Your Data
Criminal forums collect user accounts, messages, trade histories, credential-distribution records, and discussion data tied to cybercrime and combo-list ecosystems.
Recent Developments
The Exploit.In combo list continues to circulate within the cybercrime ecosystem more than nine years after its initial distribution. The compilation has been formally cited as one of the foundational large-scale combolists alongside the AntiPublic combo list (also surfaced in late 2016 with approximately 458 million credentials) and subsequent compilations including the 2017 Breach Compilation (1.4 billion credentials), Collection #1-5 (2.7 billion credentials, surfaced January 2019), and COMB (3.27 billion credentials, surfaced February 2021). The Exploit.In compilation was indexed by Have I Been Pwned in May 2017 and redistributed by DataBreach.com on December 1, 2024. Security researcher Troy Hunt analyzed the compilation and confirmed that approximately 63 percent of the records (approximately 372 million email addresses) were not present in the contemporaneous AntiPublic combolist, indicating that the Exploit.In compilation included substantial unique data not duplicated across other combolists at the time.
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:Critical
Primary downstream threats:
- Credential stuffing against reused passwords across other platforms
- Targeted phishing campaigns using exposed email addresses
Threat vectors:
- Phishing, credential stuffing & account takeover
- Credential stuffing & account takeover
Threat Actor: Unknown (compilation distributor; original sources various prior breaches)
Unknown (compilation distributor; original sources various prior breaches)
Credential Stuffing
Attribution and method are based on available breach intelligence. Reported attack vector: Credential Stuffing.
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 Exploit.In breach?▾
The Exploit.In combo list is a large-scale aggregated credential compilation that surfaced publicly in approximately October 2016 through distribution on the Russian-language Exploit.in cybercrime forum. The compilation aggregates email addresses and passwords from numerous prior unrelated breaches…
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
Cross-source
9ghz
Cross-source
BreachAware
Cross-source
BreachDirectory
Cross-source
BreachForums_Official_Index
Cross-source
DataViper.io
Cross-source
Dehashed
Cross-source
HackNotice.com
Cross-source
Leak-Lookup (+2)
ObscureIQ Intelligence
ObscureIQ proprietary analysis
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