BTG: A Bridge to Graph machine learning in telecommunications fraud detection

Telecommunications fraud runs rampant recently around the world. Therefore, how to effectively detect fraudsters has become an increasingly challenging problem. However, previous studies either assume that the samples are independent of each other and use non-graph methods, or use local subgraphs with good connectivity for graph-based anomaly detection. Few prior works have performed graph-based fraud detection on real-world Call Detail Records (CDR) meta data sets with sparse connectivity. To solve this problem, we propose an end-to-end telecommunications fraud detection framework named Bridge To Graph (BTG). BTG leverages the subscriber synergy behavior to reconstruct connectivity, which bridges the gap between sparse connectivity data and graph machine learning. Concretely, we extract multi-model features from meta data and perform Box–Cox transformation first. Then, aiming at the sparse connectivity of real-world CDR meta data, the graph is reconstructed through dimensionally selectable link prediction of node similarity. Finally, the reconstructed graph and node features are input into the graph machine learning module for node embedding representation learning and fraud node classification. Comprehensive experiments on the real-world telecommunications network CDR data set show that our proposed method outperforms the classic methods in many metrics. Beyond telecom fraud detection, our method can also be extended to anomaly detection scenarios with no graph or sparse connectivity graph.