Installed SSH.NET 2020.0.1 as a nuget package in a clean Visual Studio C# project, and ran the following code - which immediately triggered multiple AntiVirus notifications which ended up quarantining the application.

SftpClient sftp = new SftpClient("hostname", "user", new PrivateKeyFile(@"C:\Path\to\id_rsa"));
sftp.Connect();

The cited threat from AV was that it was acting like: not-a-virus:PDM:AdWare.NSIS.ConvertAd.bCb.