It is a virus. Run Norton Antivirus, it should detect it. Also, check your startup folder to see if there is a network program in there. If so, you do have a virus.
It is possible that it may not be a virus. It is a visual basic script file which can be just a regular file.
But if you have been on Mirc or other chat channels or are connected to a LAN and have a network program in your start-up folder, it is the network.vbs virus.
You need to run Norton to be sure.
I had this virus once, it was a pain to get rid of.
If you are on a LAN or go into chat channels like Mirc with a fast connection, you need to get a firewall and have Norton Antivirus when you are in the channels.