Enhancing Ethereum Fraud Detection via Generative and Contrastive Self-supervision
Zhejiang University of Technology（浙江工业大学）；Binjiang Institute of Artificial Intelligence, ZJUT（浙江工业大学滨江人工智能研究院）；Science and Technology on Communication Information Security Control Laboratory（通信信息安全控制技术实验室）
The rampant fraudulent activities on Ethereum hinder the healthy development of the blockchain ecosystem, necessitating the reinforcement of regulations. However, multiple imbalances involving account interaction frequencies and interaction types in the Ethereum transaction environment pose significant challenges to data mining-based fraud detection research. To address this, we first propose the concept of meta-interactions to refine interaction behaviors in Ethereum, and based on this, we present a dual self-supervision enhanced Ethereum fraud detection framework, named Meta-IFD. This framework initially introduces a generative self-supervision mechanism to augment the interaction features of accounts, followed by a contrastive self-supervision mechanism to differentiate various behavior patterns, and ultimately characterizes the behavioral representations of accounts and mines potential fraud risks through multi-view interaction feature learning. Extensive experiments on real Ethereum datasets demonstrate the effectiveness and superiority of our framework in detecting common Ethereum fraud behaviors such as Ponzi schemes and phishing scams. Additionally, the generative module can effectively alleviate the interaction distribution imbalance in Ethereum data, while the contrastive module significantly enhances the framework's ability to distinguish different behavior patterns. The source code will be available in https://github.com/GISec-Team/Meta-IFD.
National University of Singapore（新加坡国立大学）；Georgia Institute of Technology（佐治亚理工学院）
As various forms of fraud proliferate on Ethereum, it is imperative to safeguard against these malicious activities to protect susceptible users from being victimized. While current studies solely rely on graph-based fraud detection approaches, it is argued that they may not be well-suited for dealing with highly repetitive, skew-distributed and heterogeneous Ethereum transactions. To address these challenges, we propose BERT4ETH, a universal pre-trained Transformer encoder that serves as an account representation extractor for detecting various fraud behaviors on Ethereum. BERT4ETH features t…
University of Illinois at Chicago（伊利诺伊大学芝加哥分校）；GrabTaxi Holdings Pte Ltd（GrabTaxi控股私人有限公司）
Fraud detection problems are usually formulated as a machine learning problem on a graph. Recently, Graph Neural Networks (GNNs) have shown solid performance on fraud detection. The successes of most previous methods heavily rely on rich node features and high-fidelity labels. However, labeled data is scarce in large-scale industrial problems, especially for fraud detection where new patterns emerge from time to time. Meanwhile, node features are also limited due to privacy and other constraints. In this paper, two improvements are proposed: 1) We design a graph transformation method capturing…
Ben Gurion University of the Negev（内盖夫本-古里安大学）；HUB Security（HUB安全公司）
Since the inception of Bitcoin in 2009, the market of cryptocurrencies has grown beyond initial expectations as daily trades exceed $10 billion. As industries become automated, the need for an automated fraud detector becomes very apparent. Detecting anomalies in real time prevents potential accidents and economic losses. Anomaly detection in multivariate time series data poses a particular challenge because it requires simultaneous consideration of temporal dependencies and relationships between variables. Identifying an anomaly in real time is not an easy task specifically because of the exa…
Rethinking Contrastive Learning in Graph Anomaly Detection: A Clean-View Perspective
College of Intelligence and Computing, Tianjin University（天津大学智能计算学院）；Guangdong Laboratory of Artificial Intelligence and Digital Economy (SZ)（广东人工智能与数字经济实验室（深圳））；Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences（深圳先进技术研究院，中国科学院）
The University of Tokyo（东京大学）；National Institute of Advanced Industrial Science and Technology (AIST)（国立先进工业科学技术研究所（AIST））
While transactions with cryptocurrencies such as Ethereum are becoming more prevalent, fraud and other criminal transactions are not uncommon. Graph analysis algorithms and machine learning techniques detect suspicious transactions that lead to phishing in large transaction networks. Many graph neural network (GNN) models have been proposed to apply deep learning techniques to graph structures. Although there is research on phishing detection using GNN models in the Ethereum transaction network, models that address the scale of the number of vertices and edges and the imbalance of labels have …
Anomaly detection on the attributed network has recently received increasing attention in many research fields, such as cybernetic anomaly detection and financial fraud detection. With the wide application of deep learning on graph representations, existing approaches choose to apply euclidean graph encoders as their backbone, which may lose important hierarchical information, especially in complex networks. To tackle this problem, we propose an efficient anomaly detection framework using hyperbolic self-supervised contrastive learning. Specifically, we first conduct the data augmentation by p…
Incremental Outlier Detection Modelling Using Streaming Analytics in Finance & Health Care
National Institute of Technology Warangal（瓦朗加尔国家理工学院）；Jawaharlal Nehru Technological University – Gurajada Vizianagaram (JNTU-GV)（贾瓦哈拉尔·尼赫鲁技术大学古拉贾达维齐亚纳格拉姆分校）
University of Maryland, College Park（马里兰大学帕克分校）；Capital One（第一资本金融公司）
Tabular data underpins numerous high-impact applications of machine learning from fraud detection to genomics and healthcare. Classical approaches to solving tabular problems, such as gradient boosting and random forests, are widely used by practitioners. However, recent deep learning methods have achieved a degree of performance competitive with popular techniques. We devise a hybrid deep learning approach to solving tabular data problems. Our method, SAINT, performs attention over both rows and columns, and it includes an enhanced embedding method. We also study a new contrastive self-superv…
Unsupervised Detection of Fraudulent Transactions in E-commerce Using Contrastive Learning
Columbia University（哥伦比亚大学）；New York University（纽约大学）；University of Pennsylvania（宾夕法尼亚大学）；Georgia Institute of Technology（佐治亚理工学院）；University of Michigan（密歇根大学）
LMAE4Eth: Generalizable and Robust Ethereum Fraud Detection by Exploring Transaction Semantics and Masked Graph Embedding
Yantai Research Institute, Harbin Engineering University（哈尔滨工程大学烟台研究院）；Hangzhou Research Institute, Xidian University（西安电子科技大学杭州研究院）；College of Computer Science, Zhejiang University（浙江大学计算机学院）
Grad: Guided Relation Diffusion Generation for Graph Augmentation in Graph Fraud Detection
Tongji University Shanghai China；The University of New South Wales Sydney Australia；Tongji University \& Shanghai Artificial Intelligence Laboratory Shanghai China；Wechat Pay, Tencent Inc. Shenzhen China；Tongji University；The University of New South Wales；Tongji University \& Shanghai Artificial Intelligence Laboratory；Wechat Pay, Tencent Inc.
Advertising click fraud detection plays one of the vital roles in current E-commerce websites as advertising is an essential component of its business model. It aims at, given a set of corresponding features, e.g., demographic information of users and statistical features of clicks, predicting whether a click is fraudulent or not in the community. Recent efforts attempted to incorporate attributed behavior sequence and heterogeneous network for extracting complex features of users and achieved significant effects on click fraud detection. In this paper, we propose a Multimodal and Contrastive …
TU Kaiserslautern（凯泽斯劳滕工业大学）；Fraunhofer ITWM（弗劳恩霍夫工业数学研究所）
In this paper, we introduce the Vehicle Claims dataset, consisting of fraudulent insurance claims for automotive repairs. The data belongs to the more broad category of Auditing data, which includes also Journals and Network Intrusion data. Insurance claim data are distinctively different from other auditing data (such as network intrusion data) in their high number of categorical attributes. We tackle the common problem of missing benchmark datasets for anomaly detection: datasets are mostly confidential, and the public tabular datasets do not contain relevant and sufficient categorical attri…
Faculty of Information Science and Engineering（信息科学与工程学院）；College of Computer Science and Engineering（计算机科学与工程学院）；Department of Computer Science and Engineering（计算机科学与工程系）；Department of Computer Science（计算机科学系）
Arizona State University（亚利桑那州立大学）；Bytedance AI Lab（字节跳动人工智能实验室）
Graphs are present in many real-world applications, such as financial fraud detection, commercial recommendation, and social network analysis. But given the high cost of graph annotation or labeling, we face a severe graph label-scarcity problem, i.e., a graph might have a few labeled nodes. One example of such a problem is the so-called \textit{few-shot node classification}. A predominant approach to this problem resorts to \textit{episodic meta-learning}. In this work, we challenge the status quo by asking a fundamental question whether meta-learning is a must for few-shot node classificatio…
Temporal Contrastive Transformer for Financial Crime Detection: Self-Supervised Sequence Embeddings via Predictive Contrastive Coding
NICE Actimize
本文提出了一种名为时间对比变压器（TCT）的表示学习框架，旨在捕捉金融交易序列中的时间动态。通过自监督对比目标训练模型，生成编码时间行为模式的嵌入，以支持下游的欺诈检测任务。实验结果显示，嵌入本身能实现有意义的预测性能（AUC 0.8644），但结合领域工程特征时，性能提升不显著（AUC 0.9205 vs. 0.9245），表明学习到的表示与现有特征抽象有较大重叠。这些发现表明TCT是一种有前景的表示学习方法，能够捕捉相关的行为信号，同时凸显了在强领域特征上实现加性价值的挑战。
