Brinztech Alert: CRITICAL: Polish Lender “SuperGrosz” Breached; 1.4M Client Financial Records (PESEL, PII) Sold for $800

Dark Web News Analysis

The dark web news reports a major data breach and sale of the complete customer database from “SuperGrosz,” a Polish loan lender. The data is for sale on a hacker forum.

Key details claimed by the seller:

• Source: SuperGrosz (Polish Loan Lender).
• Platform (Inferred): The filename fos_user.csv is the “smoking gun.” It is the default user table for FOSUserBundle, a popular user management bundle for the Symfony PHP framework.
• Data Size: 1.4 million rows (customers).
• Data Content (Inferred): As a loan lender, the fos_user table (and associated data) is critically sensitive. It almost certainly contains:
  • Full PII (Name, Address, Email, Phone).
  • PESEL (Polish National ID & Tax Number).
  • Hashed Passwords and Salts.
  • Potentially related data on loan status, bank accounts, or income.
• Data Timestamp: Data spans from 2017 to 2025, indicating the data is extremely fresh and was exfiltrated from a live production database.
• Price: $800 (BTC/XMR), with an “exclusive sale” (one buyer only) claim.

This represents a severe compromise of a major financial institution’s core user database, likely stemming from an active, unpatched vulnerability.

Key Cybersecurity Insights

This alleged leak signifies a critical security incident with several catastrophic implications:

1. CRITICAL Financial PII Leak: This is the most severe threat. A loan lender’s database contains the “financial DNA” of its customers. The leak of 1.4M PESEL numbers combined with PII and contact info is a goldmine for high-friction identity theft. Attackers can:
   • Apply for new loans, credit cards, and bank accounts in victims’ names.
   • Conduct hyper-targeted financial fraud.
   • Commit tax fraud and other forms of identity theft.
2. “Fresh” Data = Active, Unpatched Breach: The 2025 timestamp proves this is not an old backup. The attacker exfiltrated this data very recently. This means the vulnerability (likely SQL Injection or RCE in the Symfony application) is still open, and the attacker may still have access to the live system.
3. WIDER CAMPAIGN (Link to ITAKA): This breach uses the exact same “smoking gun” (fos_user.csv) as the recent ITAKA (Polish travel) breach. This is NOT a coincidence. It strongly indicates a common, unpatched vulnerability in a popular Symfony plugin used in Poland, or a single compromised third-party developer/agency that built both sites. This is a systemic, ongoing campaign.
4. Suspiciously Low Price: $800 for 1.4M fresh financial records is absurdly low. This suggests the seller’s motive may be to cause maximum chaos and damage by ensuring the data is distributed quickly and widely at a low barrier to entry, rather than maximizing profit.
5. Catastrophic GDPR Failure (Poland): This is a worst-case scenario breach for a financial institution under the GDPR.
   • Mandatory 72-Hour Reporting: SuperGrosz must report this to the Polish Data Protection Authority (UODO – Urząd Ochrony Danych Osobowych) within 72 hours of awareness.
   • Mandatory User Notification: A breach of financial PII and PESEL numbers is a “high risk,” mandating the notification of all 1.4M users.
   • Fines: The fines from UODO and the financial regulator (KNF) will be severe.

Mitigation Strategies

This requires an immediate, crisis-level response from SuperGrosz and a national alert for other Polish companies.

1. For SuperGrosz:
   • IMMEDIATE Investigation & Containment: Activate the Incident Response Plan now. Engage an external DFIR firm. Assume the breach is active. The top priority is to find and patch the vulnerability (likely SQLi in the Symfony/FOSUserBundle app).
   • MANDATORY: Force Password Reset: Immediately force a password reset for all 1.4 million user accounts.
   • MANDATORY: Regulatory Reporting: Contact the UODO and KNF immediately to meet the 72-hour GDPR deadline.
   • MANDATORY: User Notification: Prepare and send a clear, transparent breach notification (in Polish) to all affected customers, warning them of the specific and severe risk of identity theft, loan fraud, and the leak of their PESEL number.
   • Harden Security: Enforce MFA (especially for admins), audit password hashing (must be bcrypt or Argon2), and conduct a full code audit of the Symfony application.
2. For Affected Customers (SuperGrosz Users):
   • Assume your full financial identity (including PESEL) is public.
   • CRITICAL: Monitor Credit Reports: Immediately contact the Polish credit bureau (BIK – Biuro Informacji Kredytowej) to monitor for fraudulent loan or credit applications.
   • Password Rotation: If you reused your SuperGrosz password on any other site (email, bank, etc.), change those passwords now.
   • Extreme Phishing/Vishing Vigilance: Be extremely suspicious of any unsolicited calls, SMS, or emails. Scammers will call you, pretend to be your bank or the government, and use your real PESEL number to “prove” their identity. NEVER give out new information.

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Questions or Feedback? This analysis is based on threat intelligence from a dark web forum. A fresh breach of a major EU financial institution, especially one linked to a wider campaign, carries severe, immediate risks for customers and catastrophic regulatory penalties. Brinztech provides cybersecurity services worldwide and does not endorse or guarantee the accuracy of external claims. For any inquiries or to report this post, please email: contact@brinztech.com