What's that MacScan one under Devices? Again, the SMBShare is most likely something like a printer maybe sharing out it's memory stick reader, a wireless router all of a sudden configured to share a resource plugged into the USB port on it (even though there may not be anything plugged into it), etc. Can you provide a list of devices on your network (don't overlook things like Smart TVs, newer stereo receivers, a media sharing app on an iPhone or another iOS device, even a media sharing app on a Mac.
One thing you can do is go to a Terminal window and ping smbshare and see what you get in response. If it resolves to an IP address, find out what that IP belong to by looking in your connected devices list on your router config page or by doing a LAN IP scan or by just looking at the IPs of all the devices on the network until you find the one that matches. Once you do, something on that device is advertising this share name... find it and disable it.