Three Birds With One Stone: User Intention Understanding and Influential Neighbor Disclosure for Injection Attack Detection
Zhihai Yang, Qindong Sun, Zhaoli Liu · IEEE Transactions on Information Forensics and Security · 2022
Recommender system, as a data-driven way to help customers locate products that match their interests, is increasingly critical for providing competitive customer suggestions in many web services. However, recommender systems are highly vulnerable to malicious injection attacks due to their fundamental vulnerabilities and openness. With the endless emergence of new attacks, how to provide a feasible way for defending different malicious threats against online recommendations is still an under-explored issue. In this paper, we explore a new way to defend malicious injection attacks through user intention understanding and influential neighbour disclosure. Specifically, we propose a detection approach, termedTBOS(ThreeBirds withOneStone), to deal with different malicious threats. InTBOS, we first develop the discrimination of attack target by combining global influence evaluation and risk attitude estimation of users. In order to makeTBOScontrollable, second, we propose to incorporate an optimal denoising mechanism to remove disturbed information before detection. To enhance the representativeness and predictability of detection model, finally, we propose to leverage a behavioral label propagation mechanism based on constructed label space for the determination of malicious injection behaviors. Extensive experiments on both synthetic and real data demonstrate thatTBOSoutperforms all baselines in different cases. Particularly, the detection performance ofTBOScan achieve an improvement of 6.08% FAR (false alarm rate) for optimal-injection attacks, an improvement of 3.83% FAR in average for co-visitation injection attacks, as well as an improvement of 2.3% for profile injection attacks over benchmarks in terms of FAR while keeping the highest DR (detection rate). Additional experiments on real-world data show thatTBOSbrings an improvement with the advantage of 6.5% FAR in average compared with baselines.