‘Shared’ are simply other devices that are announcing the services that they are running on the local network. Apple use the Bluescreen PC icon but it may not be an actual PC. That is a default icon for unknown devices.
Simply go to System Preferences>Sharing>File sharing>Options>Uncheck “Share file and folders using SMB(Windows) … Actually you need to uncheck all boxes under SHARED.
The “shared” section under the sidebar is Apple’s Bonjour protocol that allows for detection of other computers that support Bonjour. In the case of a computer being shown in the sidebar, the computer is not connected until you click it and authenticate.
For example, most times users come across an unknown shared device in their Sidebar it’s because it belongs to a printer that is also connected to the same Wi-Fi network as their Mac is. That is, if you have a single Mac at home connected to Wi-Fi, then that Mac is connected to a network.
Computers and other Network resources that are “Shared” are made visible (and possibly accessible) to you. This is not symmetrical, i.e., this does NOT make YOUR computer visible to others, and this most certainly do NOT make your computer accessible to others.
Can a Mac be hacked remotely?
In fact, it’s possible to remotely compromise a brand new Mac the first time it connects to Wi-Fi. That attack, which researchers will demonstrate Thursday at the Black Hat security conference in Las Vegas, targets enterprise Macs that use Apple’s Device Enrollment Program and its Mobile Device Management platform.
- Press the Start button, then select Settings > Devices.
- Click the device you want to remove.
- Click Remove Device.
- Click Yes to confirm that you want to remove this device.
- Restart your device, and see if the device is still connected to your computer.
Stop sharing a file
- Open the homescreen for Google Drive, Google Docs, Google Sheets, or Google Slides.
- Select a file or folder.
- Tap Share or Share .
- Find the person you want to stop sharing with.
- To the right of their name, tap the Down arrow. Remove.
- To save changes, tap Save.
Shared device mode allows you to configure an Android device so that it can be easily shared by multiple employees. Employees can sign in and access customer information quickly.