ClickOnce is a deployment solution that enables fast, easy delivery of packaged software. It is commonly used by organizations to deploy both internal and production-grade software packages along with their respective updates. By allowing end-users to accept the requested permissions of the software package without the intervention of an administrator, ClickOnce simplifies the deployment and use of robust software solutions. It also provides an excellent opportunity for malicious actors to establish a foothold in your network. In this talk, we will discuss how we combined ClickOnce technology and existing phishing techniques into a new methodology for establishing an initial presence in an environment. By minimizing user interaction, we only require that the user is fooled for "one click" - after that, we already have a foothold in their environment and are ready to pivot and escalate further.