Malicious npm postinstall/preinstall Lifecycle Script Spawning cmd.exe or sh

This rule detects when a node.exe process, commonly used for executing npm lifecycle hooks (such as preinstall, postinstall, or various .cjs scripts), spawns suspicious child processes including shells (cmd.exe, powershell.exe, sh, bash) or scripting engines (wscript.exe, cscript.exe). This pattern is frequently observed in malicious npm packages designed to achieve code execution on a developer's machine during the package installation or build process.