SharpSilentChrome is a Windows CLI tool that silently installs browser extensions on Google Chrome and Microsoft Edge by directly modifying the browser's 'Preferences' and 'Secure Preferences' files. It implements the technique first published in academic research and popularized by public Python scripts. The tool supports two modes: 'install' which injects an extension and computes the required HMAC integrity checks, and 'revert' which restores backup copies of the preferences files. It can kill and restart browser processes for the target user to apply changes immediately. The code is a C# port of existing Python PoC code, targeting .NET Framework 4.8 with dependencies on Newtonsoft.Json for JSON manipulation and System.Management for WMI process queries. It relies on hardcoded HMAC seeds for Chrome (noted as empty for Edge) and performs SID-to-username resolution via Win32 API and registry. The repository serves primarily as an operational tool for red team exercises, with no unit tests, modular architecture, or reusable components beyond the immediate use case.