The widespread presence of peripheral devices in households, connecting to desktops and laptops, creates a substantial security vulnerability. These devices can be manipulated at the hardware level, allowing unauthorized access to host systems. Although modern operating systems like Windows, Linux, and Mac incorporate software security measures to counteract malicious keylogging programs, these defenses can be evaded through a combination of encryption, decryption, and hardware techniques. This evasion makes them effectively undetectable at the OS level, as demonstrated in prior research. The existing literature emphasizes the considerable threat such devices pose to future users. In this study, we develop a custom malicious keyboard at a low cost, providing a practical demonstration of potential attacks. Through this research, our aim is to illuminate the inherent vulnerabilities within peripheral devices, highlighting the critical need to bolster hardware security measures to safeguard against these covert and pernicious threats.