CreateRemoteThread Injection is a technique used by cyber attackers to run malicious code within another, legitimate process on a Windows system. By leveraging the 'CreateRemoteThread' function, attackers can force a trusted program to execute harmful instructions on their behalf. This makes the malicious activity harder to detect, as it appears to come from a safe application. Security tools may struggle to distinguish between normal and injected behavior, making this method popular among malware authors for evading antivirus software and gaining unauthorized control over systems.