Android has a strict permission management mechanism. Any applications that try to run on the Android system need to obtain permission. In this paper, we propose an efficient method of detecting malicious applications in the Android system. First, hundreds of permissions are classified into different groups. The application programming interfaces (APIs) associated with permissions that can interact with the outside environment are called sink functions. The APIs associated with other permissions are called taint functions. e construct association tables for block variables and function variables of each application. Malicious applications can then be detected by using the static taint-propagation method to analyze these tables.