Development of New Methods for Detection and Control of Credit Card Fraud Attacks
Alexander Stotsky
TL;DR
This paper tackles the problem of detecting and controlling credit card fraud attacks in real time, where attacks manifest as rapid sequences of fraudulent transactions. It combines a moving-window confidence interval with exponential forgetting to adapt to evolving cardholder behavior and detect outliers, with a fraud risk scoring approach to identify the onset of an attack based on multiple risk factors. Detection is followed by control strategies that adjust the interval and impose mitigations (e.g., block/limit high-risk transactions, constrain MCCs, and require extra verification) to minimize losses. The approach is evaluated conceptually on a dataset of approximately $24.4$ million transactions from IBM, and the authors call for robust real-time algorithms and simulation tools to prepare for emerging attack types in crisis scenarios.
Abstract
Credit card fraud causes significant financial losses and frequently occurs as fraud attack, defined as short-term sequence of fraudulent transactions associated with high transaction rates and amounts, business areas historically tied to fraud, unusual transaction times and locations and different types of errors. Confidence interval method in the moving window with exponential forgetting is proposed in this report which allows to capture recent changes in the shopping behaviour of the cardholder, detect fraudulent amounts and mitigate the attack. Fraud risk scoring method is used for estimation of the intensity of the fraudulent activity via monitoring of the transaction rates, merchant category codes, times and some other factors for detection of the start of the attack. The development and verification are based on detailed analysis of the transaction patterns from the dataset, which represents an extensive collection of around 24.4 million credit card transactions from IBM financial database. Recommendations for further development of the detection techniques are also presented.
