Top 20 NuGet anti Packages
Rule based HTML sanitizer using a white list. Documentation at: https://github.com/Vereyon/HtmlRuleSanitizer
Google ReCaptcha wrapper class for quick and easy validation (injectable service for ASP.NET Core apps).
A package to secure all controllers actions in your application by default by disallowing anonymous access, and requiring each HttpPost action to be passed an anti-forgery token. Anonymous access to a controller action needs to be explicitly set by use of an attribute.