Installer package abuse is the misuse of a software setup process so attacker-controlled code executes while a program is being installed. Installers are trusted by users and often run with elevated permissions, which makes them a valuable delivery path for malware. Attackers may hide scripts, dropper logic, or malicious components inside a setup file, or trigger code through custom actions, post-install commands, or bundled dependencies.
This matters because the installation step is where security controls are often weakest: users expect change, and endpoints may grant broad access to installers. In real attacks, installer abuse can provide initial access, persistence, or payload deployment while appearing like a normal software install. Defenses include downloading software only from approved sources, verifying signatures and hashes, restricting who can install software, and monitoring for unusual child processes, network connections, or file drops launched during setup.