A DIY add-on is a user-built accessory or modification that changes or extends how a device works. It may add hardware, software, or both, and is usually created or assembled outside the device manufacturer’s standard product line.
In cyber security, an add-on can affect a device’s security and reliability because it may introduce new components, firmware, or code that has not been independently tested. For example, a custom VR tracking accessory may rely on sensors and software to estimate position. Builders should verify the source and integrity of its software, check compatibility, and test performance; defenders should treat unfamiliar peripherals as part of the device’s attack surface.