WeChat User Geolocation Method Based on Probe Deployment Optimization and the User Order

WeChat is a globally popular social application, and conducting research on WeChat user geolocation can help locate malicious users and verify the security of user privacy protection policies. The existing WeChat user geolocation methods have high geolocation accuracy, but the geolocation process often requires frequent queries of WeChat LBSD services, resulting in low geolocation efficiency. Therefore, we propose a WeChat user geolocation method based on deployment optimization and the user order. This method quickly scans the target area by planning the movement path of the probe, then calculates the probability of user discovery at different distances, divides the target area into grids, and updates the coverage rate of sub grids within its scanning range as the probe moves. Based on the probe coverage rate, weak coverage areas are scanned to avoid potential target omission issues that may occur when the probe scans along the movement path. In the user geolocation phase, the first step is to use the reported distance of the target user and the order relationship between users to determine a fine-grained true distance range. Then, based on the true distance boundary, a trilateral measurement method is used to preliminarily locate the target user. Finally, a weighted least squares method is used to accurately calculate the user's position coordinates. The experimental results show that compared with the existing representative methods WLSG, RRABG, and MSAG, the proposed method significantly reduces the number of LBSD queries while ensuring geolocation accuracy. In the user discovery phase, the average number of LBSD queries is reduced by 46.24% −66.76%. During the user geolocation phase, the average number of LBSD queries decreased by 19.98% −56.10%.