ExtFPDet: A CNN-Based Detection Framework for Browser Extensions Fingerprinting

With the widespread use of modern browser extensions, user experience has been significantly enhanced via embedding ancillary functionality into the original webpage. The rapid development of Web tracking technology has raised privacy and security concerns, as it generates a unique identifier for users according to the diversity of installed extensions and further prompts the profiling of users. However, due to the ignorance of potential privacy risks, there is no effective method to detect browser extension fingerprinting. In this paper, we propose ExtFPDet, a CNN-based detection framework to recognize browser extension fingerprinting in websites, which fills the gap in this area. Based on the preliminary investigation, the approaches to fingerprint browser extensions can be summarized into 2 categories according to the distinctive behaviors, including resource traversing and side-channel exploring. In order to extract effective features to reflect extensions fingerprinting, ExtFPDet focuses on the structure and content in the program dependency graph of Javascript files. The generated feature vector assists the CNN-based classification model to detect the extension fingerprinting, for which we perform a systematic detection on Tranco top 10K websites. Eventually, the result is evaluated by randomly sampling and manually checking, which shows superior detection capabilities of ExtFPDet.