Identifying a security breach caused when a computer-based software application uses a computer-based web browser application, including identifying at least one function within a computer-based software application that causes a computer-based web browser application to access data from a source that is external to the software application, at least partially replacing the data with malicious content that is configured to cause a predefined action to occur when the malicious content is accessed by the web browser application, where the predefined action is associated with a known security breach when the predefined action occurs subsequent to the malicious content being accessed by the web browser application, causing the software application to perform the function, and determining whether the predefined action is performed.