Process injection is a technique used by cyber attackers and malware to insert malicious code into the memory space of a legitimate process running on a computer. By doing this, the malicious code can run under the guise of trusted software, making it much harder for security tools and users to detect its presence. This method is often used to bypass security controls, maintain persistence, or steal sensitive information without drawing attention. Common forms of process injection include DLL injection, code cave exploitation, and process hollowing.