var clamConfig = app.Configuration.GetConnectionString("antivirus");
if (string.IsNullOrEmpty(clamConfig)) throw new Exception("Missing antivirus configuration");

var ClamUri = new Uri(clamConfig);
    
 ...
 
 var clam = new ClamClient(ClamUri.Host, ClamUri.Port);
 var scanResult = await clam.SendAndScanFileAsync(stream);
 
 ...
 
ErrorMessage = scanResult.Result switch { 
  ClamScanResults.VirusDetected => $"Virus {scanResult.InfectedFiles.First().VirusName} detected",
  ClamScanResults.Error => $"Error with virus scanning.  Please try again",
  _ => string.Empty
},