Dueling Network Data Breach
Status: Confirmed
Breach Intelligence Summary
Entity: Dueling Network · Actor: Unknown · Source: DataBreach.com / ObscureIQ intelligence
Attack: Credential Compromise via Compromised credentials
Timeline: Breach (Mar, 2017) · Reported (Mar, 2020) · Leak (2/12/25)
Exposure: 6.5M+ records · Email, IP Address, IP addresses, Password, Passwords, Usernames
Status: Confirmed · Risk: Moderate (Account takeover)
Summary
In March 2017 Dueling Network—a once-popular online platform for Yu-Gi-Oh fans—suffered a significant data breach that compromised roughly 6.48 million user accounts. Although the main site had been taken offline in 2016 due to a cease-and-desist order its forum remained active leaving a trove of user data exposed. Hackers exploited a vulnerability in MySQL to gain unauthorized access to the database which stored email addresses IP addresses usernames and passwords hashed using the weak MD5 algorithm. This outdated hashing method made it easier for attackers to potentially crack the passwords putting users at risk if they reused those credentials elsewhere.
About Dueling Network
Dueling Network is the organization affected by this breach. User data may have been generated through account creation, service usage, or business operations.
If you have interacted with Dueling Network in any capacity, your data may be included in this breach.
Threat Actor: Unknown
The threat actor responsible for this breach has not been publicly identified or confirmed at this time.
- Compromised credentials
Breach Exploitation Status
Moderate
Status
Detected
Detected
Possible
Unknown
Unknown
1–3 years
Email addresses and usernames persist but credentials may rotate. Phishing risk remains elevated during this window.
Data Points Exposed
Dark Web Verification
Status: Confirmed
- Dataset containing approximately 6.5M+ records has been identified in breach intelligence sources.
- The data is indexed and searchable across breach notification platforms.
Impact
This breach carries moderate risk due to the nature of exposed data fields and the scale of affected records.
- Targeted phishing referencing Dueling Network accounts or services
- Credential stuffing against accounts sharing the same password
- Physical mail scams and address-based identity verification fraud
- Data broker enrichment and resale
Recommendations for Impacted Individuals
If you believe your information may be included:
Non-clients may request a breach impact review.
Dueling Network account updates
Password reset requests
Verify directly through official channels.
Email compromise is often the first pivot point.
Frequently Asked Questions
In Mar, 2017, Dueling Network experienced a data breach that resulted in the exposure of approximately 6.5M+ records containing personal information.
The exposed data includes Email, IP Address, IP addresses, Password, Passwords, Usernames.
Approximately 6.5M+ records were affected based on current breach intelligence.
Yes. This breach is treated as confirmed based on data observed in breach intelligence platforms.
Data circulation has been detected across breach-sharing channels. Downstream exploitation risk exists based on the nature of the exposed fields.
Rotate passwords associated with Dueling Network, enable multi-factor authentication on email and financial accounts, and monitor for suspicious activity.
Protect Yourself
Check If You’re Affected
Enter your email to check if your data appears in this breach.
Get Free Breach Alerts
Be the first to know when new breaches are disclosed. Free forever.
High-Risk? Get an Exposure Audit
Executives, public figures, and high-net-worth individuals face elevated risk. Our team provides full-spectrum exposure audits and threat monitoring.
Corporate Accountability
Organizations that collect personal data have a duty to implement reasonable safeguards and to notify affected individuals when breaches occur.
Scope assessments may evolve as investigations continue. Users should not rely solely on early estimates when making risk decisions.
ObscureIQ Advisory
We combine proprietary dark web access with commercial and restricted breach intelligence to verify exposure and assess real-world risk.
- A public-facing individual
- A high-profile executive
- A customer of Dueling Network
- Or simply concerned about credential reuse
We can confirm whether your information is circulating and evaluate downstream threat vectors.