ELEVATED RISK BREACH

Nihonomaru Data Breach


Status: Confirmed

1.7M+Records
Dec, 2015Breach
Aug, 2016Data Posted
6/10Severity
ModerateThreat Level

Breach Intelligence Summary


Entity: Nihonomaru · Actor: Unknown · Source: DataBreach.com / ObscureIQ intelligence

Attack: Data Exfiltration via Vulnerability exploitation

Timeline: Breach (Dec, 2015) · Reported (Aug, 2016) · Leak (Aug, 2016)

Exposure: 1.7M+ records · Email, IP addresses, Password, Passwords, Usernames

Status: Confirmed · Risk: Moderate (Account takeover)

Summary

In December 2015 Nihonomaru an anime community website experienced a significant data breach when its vBulletin forum was hacked. This breach resulted in the exposure of approximately 1.7 million user accounts compromising sensitive information such as email addresses IP addresses usernames and salted password hashes. The attack targeted vulnerabilities within the vBulletin forum software a platform widely used for online communities. Although specific details regarding the exploitation method remain undisclosed it is evident that the attackers leveraged these security gaps to gain unauthorized access to Nihonomaru’s user database.

About Nihonomaru

Nihonomaru 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 Nihonomaru 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.

Reported or suspected access method:
  • Vulnerability exploitation

Breach Exploitation Status

Threat Activity:
Moderate
Signal
Status
Dark web marketplace listings
Detected
Credential stuffing list overlap
Detected
Phishing campaign relevance
Possible
Ransomware affiliate crossover
Unknown
Law enforcement investigation visibility
Unknown

Data Longevity:
1–3 years

Email addresses and usernames persist but credentials may rotate. Phishing risk remains elevated during this window.

Data Points Exposed

Data observed in the leaked dataset:
Email
IP addresses
Password
Passwords
Usernames
Not confirmed in dataset:
Social Security Numbers
Payment card data
Passport numbers

Dark Web Verification

Status: Confirmed

  • Dataset containing approximately 1.7M+ 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.

Primary downstream threats include:
  • Targeted phishing referencing Nihonomaru 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:

Check Your Exposure
If you are an ObscureIQ client, this breach has been indexed into your exposure profile.
Non-clients may request a breach impact review.
Expect Targeted Phishing
Watch for messages referencing:
Nihonomaru account updates
Password reset requests
Verify directly through official channels.
Secure Your Email and MFA
Enable MFA immediately on email first, then financial platforms.
Email compromise is often the first pivot point.
Rotate Reused Passwords
Change any credentials shared with your Nihonomaru account across other services.
Monitor Financial Accounts
Monitor accounts associated with your exposed email for unauthorized activity.
Suppress Personal Data
Remove exposed addresses, phone numbers, and enrichment data from broker networks and search engines.

Frequently Asked Questions

What happened in the Nihonomaru data breach?

In Dec, 2015, Nihonomaru experienced a data breach that resulted in the exposure of approximately 1.7M+ records containing personal information.

What data was exposed in the Nihonomaru breach?

The exposed data includes Email, IP addresses, Password, Passwords, Usernames.

How many records were affected in the Nihonomaru breach?

Approximately 1.7M+ records were affected based on current breach intelligence.

Is the Nihonomaru breach confirmed?

Yes. This breach is treated as confirmed based on data observed in breach intelligence platforms.

Is the Nihonomaru breach data being used by criminals?

Data circulation has been detected across breach-sharing channels. Downstream exploitation risk exists based on the nature of the exposed fields.

What should I do if I was affected by the Nihonomaru breach?

Rotate passwords associated with Nihonomaru, enable multi-factor authentication on email and financial accounts, and monitor for suspicious activity.

Protect Yourself

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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.

If you are:
  • A public-facing individual
  • A high-profile executive
  • A customer of Nihonomaru
  • Or simply concerned about credential reuse

We can confirm whether your information is circulating and evaluate downstream threat vectors.

Services
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Classification Tags

Data Exfiltration
Passwords
Email
Address