Malware injection is a cyberattack technique where malicious code is secretly inserted into legitimate software, websites, or systems. This harmful code runs unnoticed by users or administrators, enabling attackers to steal sensitive data, hijack system resources, or gain unauthorized access. Common methods include SQL injection, script injection, and file injection. Malware injection can compromise personal information, disrupt business operations, and lead to financial losses. Preventing such attacks typically involves regular software updates, strong security practices, and thorough code reviews to detect and eliminate vulnerabilities.