node.exe is the Windows executable that launches Node.js, the JavaScript runtime used to run scripts and applications outside the browser. In normal environments it is common in development, automation, and build tooling, so its presence is not suspicious by itself.
In cyber security, node.exe matters because attackers can abuse a trusted runtime to execute malicious JavaScript while blending in with legitimate activity. This is a form of interpreter abuse: the file may look familiar, but the behavior can be harmful. Defenders should watch for unusual parent-child process chains, odd command lines, unexpected network activity, and Node.js execution on systems that do not normally need it. Process context is often more valuable than file reputation alone.