VNC® provides secure remote access computers from any location for your home and organization. RFB is the protocol used in VNC and its derivatives.

This tutorial will guide you to block VNC with "WFilter Enterprise 4.0". Because blocking of VNC is not supported by default in WFilter, in this example, we uses "Customize Protocols" feature of WFilter to define the VNC protocol.

First, Add "VNC" Protocol in "Customize Protocols".

In "Customize Protocols", new a protocol named "vnc".

VNC has a pattern:
"vnc_tcp":
Type--"TCP ALL"
Format--"0"
Pattern Content--"^\x52\x46\x42\x20\x30\x30"

Second, Enable blocking of VNC in certain blocking levels.

And apply this blocking policy to certain computers.

Now, VNC will be blocked.

WFilter blocking events:

Failure connection of VNC.