Network activity by an app can be dangerous if the app is malicious. If you suspect an app of malicious network activity, but you’re not sure, you can either uninstall it or you can block its access to the network. If you know the app is malicious, uninstalling it is the way to go, however, for apps that tend to use up your network bandwidth while running in the background, you can use a simple firewall rule to block network access for an app on Windows 10.
Block network access for an app
Open Control Panel and go to the System and Security group of settings. Click Windows Defender Firewall. Alternatively, open File Explorer and enter the following in the location bar.
Control Panel\System and Security\Windows Defender Firewall
In the window that opens, click Advanced Settings in the column on the left. Note that you will need admin rights to access this setting. The Windows Defender firewall and security window will open. In the column on the left click Outbound rules.
In the column on the right, click New Rule.
In the Window that opens, select Program and click Next. On the next screen, select This Program Path, and click the browse button. Select the EXE of the app that you want to block network access to.
Click Next. You do not need to change anything else on the screens that follow. Keep clicking Next until you’re asked to enter a name for the rule. Give the rule a name that tells you what it does e.g., what app or process it blocks. Add the rule and it will be enabled by default.
When the app next tries to establish an internet connection to download something, it will not be able to. Depending on the type of app it is, you may or may not see an indication or an alert that the app is unable to connect to the internet. You will not be able to tell that internet access has been blocked at the firewall level. As such, it is up to you to remember that you’ve blocked an app from accessing the network from the firewall and enable it if you want to.
You can enable network access for the app either by editing the rule from its properties, or you can just delete the rule and allow everything to return to normal.
This will suspend all network activity for the app whether the activity occurs in the foreground, or in the background.