A postinstall script is a command or set of commands that automatically executes after a software package is installed on a system. Legitimate uses include configuring settings, downloading dependencies, or initializing services. However, in cybersecurity, postinstall scripts are a common attack vector because they can be abused by attackers to run malicious code without user knowledge. Malicious postinstall scripts may create backdoors, download additional malware, or alter system configurations, compromising system integrity and security. Security best practices recommend auditing and verifying package sources and inspecting scripts before installation to mitigate risks associated with postinstall scripts.