The webserver may get infected as the Laptop used by user is infected.It is better to have an antivirus protection on the webserver which prevents the webserver from any king of infection caused by the virus.Pix itself has an antivirus in it which will prevent any infection to pass through.Pix has the benefits which includes a modular design that allows you to add features such as intrusion prevention (IPS), anti-virus, anti-spam, anti-phishing, and URL filtering.