Detecting Business Logic Abuse in Modern Marketplaces

Understanding the Adversary Fraudsters treat online marketplaces as math problems. They look for imbalanced incentives—coupon stacking, refund loopholes, or tiered loyalty misconfigurations. Traditional vulnerability scanners miss these nuances because the issues live at the workflow level, not the HTTP level.

Instrument the Journey Map the lifecycle of a high-value transaction: account creation, inventory listing, order execution, and payout. Log critical decision points—discount validation, address verification, payout triggers—and feed that telemetry into anomaly detection pipelines. If you cannot measure the journey, you cannot defend it.

Create Abuse Stories Borrow the concept of user stories but flip it for attackers. “As a fraudulent seller, I want to mass-create listings without identity checks so I can cash out.” For each abuse story, define guardrails (rate limits, reputation scoring), observability (alerts on velocity spikes), and manual review fallbacks.

Partner With Trust and Safety Security cannot solve logic abuse alone. Trust & Safety teams hold the policy levers, while product owns customer experience. Build triage war rooms where all three groups analyze incidents, tweak product requirements, and deploy mitigations. Victory is blocking fraud with minimal friction to legitimate users.

Key Takeaway Business logic abuse is a business problem wearing a security mask. Treat it like product design—iterate, test, and keep attackers guessing.