This indicates an attempt to connect to a VNC server via a VNC client.
VNC is a free desktop sharing system that uses the Remote Frame Buffer protocol to connect remotely to another computer. Upon a successful connection, a graphical interface is provided. To establish a connection, the client side has to have the VNC client installed and the server side, the VNC server. Multiple clients can connect to a VNC server at one time. The VNC client is used most commonly for remote technical support or remote access to a personal desktop at home. The source code is open source, thus there are many software that uses slight variations of the protocol.