This article is an excerpt from the book, "The Art of Software Security Testing," and focuses on the approach and techniques used to test the security of local applications. It begins by describing local resources and interprocess communication, which make up a local applications attack surface. After describing how to enumerate the local resources an application depends on, the text then describes methods of testing several of those types of resources. It also describes how to test ActiveX objects, command-line programs, and applications use of local files and shared memory.