This paper explores the increasing prevalence of cyberattacks targeting web applications, highlighting the vulnerabilities of popular platforms like Java and Android. It examines the impact of these attacks, emphasizing the need for robust security measures. The paper delves into the role of the Software Development Life Cycle (SDLC) in mitigating security risks and discusses various approaches like agile and waterfall methodologies for developing secure web applications. It concludes by addressing key questions regarding preventing pop-ups, controlling attacks, and protecting data from intruders.