The emergence of LLM (Large Language Model) integrated virtual assistants has brought about a rapid transformation in communication dynamics. During virtual assistant development, some developers prefer to leverage the system message, also known as an initial prompt or custom prompt, for preconditioning purposes. However, it is important to recognize that an excessive reliance on this functionality raises the risk of manipulation by malicious actors who can exploit it with carefully crafted prompts. Such malicious manipulation poses a significant threat, potentially compromising the accuracy and reliability of the virtual assistant's responses. Consequently, safeguarding the virtual assistants with detection and defense mechanisms becomes of paramount importance to ensure their safety and integrity. In this study, we explored three detection and defense mechanisms aimed at countering attacks that target the system message. These mechanisms include inserting a reference key, utilizing an LLM evaluator, and implementing a Self-Reminder. To showcase the efficacy of these mechanisms, they were tested against prominent attack techniques. Our findings demonstrate that the investigated mechanisms are capable of accurately identifying and counteracting the attacks. The effectiveness of these mechanisms underscores their potential in safeguarding the integrity and reliability of virtual assistants, reinforcing the importance of their implementation in real-world scenarios. By prioritizing the security of virtual assistants, organizations can maintain user trust, preserve the integrity of the application, and uphold the high standards expected in this era of transformative technologies.