Exploiting graph metrics to detect anomalies in cross-country money transfer temporal networks

During the last decades, Anti-Financial Crime (AFC) entities and Financial Institutions have put a constantly increasing effort to reduce financial crime and detect fraudulent activities, that are changing and developing in extremely complex ways. We propose an anomaly detection approach based on network analysis to help AFC officers navigating through the high load of information that is typical of AFC data-driven scenarios. By experimenting on a large financial dataset of more than 80M cross-country wire transfers, we leverage on the properties of complex networks to develop a tool for explainable anomaly detection, that can help in identifying outliers that could be engaged in potentially malicious activities according to financial regulations. We identify a set of network metrics that provide useful insights on individual nodes; by keeping track of the evolution over time of the metric-based node rankings, we are able to highlight sudden and unexpected changes in the roles of individual nodes that deserve further attention by AFC officers. Such changes can hardly be noticed by means of current AFC practices, that sometimes can lack a higher-level, global vision of the system. This approach represents a preliminary step in the automation of AFC and AML processes, serving the purpose of facilitating the work of AFC officers by providing them with a top-down view of the picture emerging from financial data.