๐ค AI Summary
In graph neural network (GNN)-based fraud detection, severe class imbalance between fraudulent and benign nodes leads to imbalanced topological message propagation and node representation drowning. To address this, we propose MimbFD, a dual-perspective graph representation learning framework. Methodologically, MimbFD jointly models the coupled influence of graph topology and label distribution on supervised message passingโfirst formalized in this work. It introduces a topology-aware message reachability module to enhance long-range dependency capture for fraudulent nodes, and a local confusion debiasing module to mitigate feature ambiguity induced by adversarial camouflage behaviors of fraudsters. Leveraging a statistics-driven debiasing adjustment strategy during message aggregation, MimbFD achieves significant improvements over state-of-the-art methods across three public fraud detection benchmarks, demonstrating superior accuracy, robustness against adversarial perturbations, and cross-domain generalization capability.
๐ Abstract
Graph representation learning has become a mainstream method for fraud detection due to its strong expressive power, which focuses on enhancing node representations through improved neighborhood knowledge capture. However, the focus on local interactions leads to imbalanced transmission of global topological information and increased risk of node-specific information being overwhelmed during aggregation due to the imbalance between fraud and benign nodes. In this paper, we first summarize the impact of topology and class imbalance on downstream tasks in GNN-based fraud detection, as the problem of imbalanced supervisory messages is caused by fraudsters' topological behavior obfuscation and identity feature concealment. Based on statistical validation, we propose a novel dual-view graph representation learning method to mitigate Message imbalance in Fraud Detection(MimbFD). Specifically, we design a topological message reachability module for high-quality node representation learning to penetrate fraudsters' camouflage and alleviate insufficient propagation. Then, we introduce a local confounding debiasing module to adjust node representations, enhancing the stable association between node representations and labels to balance the influence of different classes. Finally, we conducted experiments on three public fraud datasets, and the results demonstrate that MimbFD exhibits outstanding performance in fraud detection.