ClickOnce is a Microsoft Windows deployment technology that lets an application install and launch with very little user interaction. It was designed to make software updates easy for end users by handling setup, updates, and execution through a trusted Windows workflow.
In cyber security, ClickOnce matters because attackers can abuse its convenience and familiarity to deliver malware with less friction than a traditional installer. A user may see a signed or routine-looking launch prompt and assume it is safe, especially when the file arrives through a convincing business pretext. Defenders should treat unexpected ClickOnce packages as security-relevant, inspect the source, verify code signatures, and monitor for unusual child processes, network connections, or credential theft behavior after launch.