Yuexin Li, Chengyu Huang, and Shumin Deng, National University of Singapore; Mei Lin Lock, NCS Cyber Special Ops-R&D; Tri Cao, National University of Singapore; Nay Oo and Hoon Wei Lim, NCS Cyber Special Ops-R&D; Bryan Hooi, National University of Singapore
Phishing attacks have inflicted substantial losses on individuals and businesses alike, necessitating the development of robust and efficient automated phishing detection approaches. Reference-based phishing detectors (RBPDs), which compare the logos on a target webpage to a known set of logos, have emerged as the state-of-the-art approach. However, a major limitation of existing RBPDs is that they rely on a manually constructed brand knowledge base, making it infeasible to scale to a large number of brands, which results in false negative errors due to the insufficient brand coverage of the knowledge base. To address this issue, we propose an automated knowledge collection pipeline, using which we collect a large-scale multimodal brand knowledge base, KnowPhish, containing 20k brands with rich information about each brand. KnowPhish can be used to boost the performance of existing RBPDs in a plug-and-play manner. A second limitation of existing RBPDs is that they solely rely on the image modality, ignoring useful textual information present in the webpage HTML. To utilize this textual information, we propose a Large Language Model (LLM)-based approach to extract brand information of webpages from text. Our resulting multimodal phishing detection approach, KnowPhish Detector (KPD), can detect phishing webpages with or without logos. We evaluate KnowPhish and KPD on a manually validated dataset, and a field study under Singapore's local context, showing substantial improvements in effectiveness and efficiency compared to state-of-the-art baselines.
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author = {Yuexin Li and Chengyu Huang and Shumin Deng and Mei Lin Lock and Tri Cao and Nay Oo and Hoon Wei Lim and Bryan Hooi},
title = {{KnowPhish}: Large Language Models Meet Multimodal Knowledge Graphs for Enhancing {Reference-Based} Phishing Detection},
booktitle = {33rd USENIX Security Symposium (USENIX Security 24)},
year = {2024},
isbn = {978-1-939133-44-1},
address = {Philadelphia, PA},
pages = {793--810},
url = {https://www.usenix.org/conference/usenixsecurity24/presentation/li-yuexin},
publisher = {USENIX Association},
month = aug
}