The Dark Web and Payments: How Cybercriminals Exploit Weak Payment Security

The number of data compromises in the United States in 2024 was 3,158 cases. Over 1.35 billion individuals were affected by those compromises, data breaches, leakage, and exposure. Behind many of these breaches are platforms built with good intentions but flawed assumptions: that APIs are secure by default, that tokenization is foolproof, or that partner systems automatically inherit enterprise-grade protections. In the embedded payments space, those assumptions can prove especially costly.

Payment data remains an incredibly valuable asset on the dark web. It is a persistent target for cybercriminals who profit from system vulnerabilities, poor credential management, and oversight gaps. For independent software vendors (ISVs) with embedded payments, this is a direct threat to platform integrity, merchant trust, and long-term viability. As attack surfaces expand, so do the risks. The consequences are both immediate and compounding.

How Payment Data Ends Up on the Dark Web

Dark web marketplaces operate with alarming efficiency. Within hours of a breach, stolen payment credentials — including card numbers, CVVs, and API tokens — can be bundled and sold to the highest bidder. These marketplaces can accelerate the scale and reach of these instances. Analysts estimate that data breaches or exposures in 2024 were up fourfold from earlier years.

These breaches typically stem from vulnerabilities introduced through weak or outdated security practices:

• Exposed APIs: Open endpoints without sufficient authentication protocols allow unauthorized access. Poorly protected API keys, especially those hardcoded or stored insecurely, are easy entry points for attackers. A 2025 report found 84% of fintechs still lacked sufficient API protection despite handling sensitive or high-value payment data.
• Gaps in Tokenization: Tokenization only protects what it fully encodes and isolates. Many platforms tokenize data in storage but overlook transit or fail to isolate token vaults from production environments.
• Environment Oversight: The growing reliance on third-party plugins and sandbox environments introduces risk vectors that often go unmonitored. Attackers exploit integration blind spots to pivot deeper into systems, so it’s critical to enforce rigorous API security reviews and ongoing partner due diligence.
• Insecure Credentials: Shared passwords, lack of multi-factor authentication (MFA), and poor credential rotation habits increase the likelihood of unauthorized access, particularly in developer and test environments.

Best Practices to Secure Embedded Payment Stacks

For ISVs embedding payments, security must be treated as a core product function. Addressing today’s threat landscape requires not only better tools but also more disciplined practices.

• Enforce API Security Hygiene: Rotate keys regularly, enforce least-privilege access, and monitor endpoint activity. Leverage token-based authentication over static credentials.
• Strengthen Tokenization Protocols: Ensure end-to-end tokenization across both data-at-rest and data-in-transit. Use segregated environments and maintain strict access controls over token vaults. As the global tokenization market grows from $3.32 billion in 2024 to a projected $12.83 billion by 2032, robust implementation becomes essential.
• Conduct Comprehensive Partner Audits: Review all third-party integrations for security posture. Require vendors and sandbox environments to meet baseline standards for encryption, access, and data handling.
• Harden Credential Management: Eliminate shared accounts. Enforce MFA across all admin and developer users. Invest in a credential manager to avoid hardcoded secrets and enable dynamic key rotation.
• Monitor the Dark Web: Employ threat intelligence tools—such as dark web monitoring services, credential exposure scanners, and brand protection platforms—to monitor forums and marketplaces for stolen credentials, leaked payment data, merchant IDs, and brand mentions. Watch for compromised API keys, bulk data dumps, and chatter about exploits targeting the platform. Early detection of these signals enables faster incident response and helps protect both merchants and customers.

Close the Gaps Before They Open Doors

The dark web mirrors the security posture of today’s embedded platforms. As payment data continues to be a prime target, ISVs that fail to ensure a secure architecture risk both their customers and their business models. Proactive security is no longer a competitive differentiator. It is a baseline expectation.