It's not always easy to ensure that your devices are completely free of viruses. Just like a real disease, you can be infected without even realising it. 
 

So it's important to have a virus scanner on all your devices. Compare it to a vaccine, it detects incoming viruses and eliminates them. So it's very important to have an anti-virus scanner to keep your computer healthy. More information on virus scanning: https://www.safeonweb.be/en/scan-your-computer
 

Unfortunately, a virus scanner does not detect all viruses (and it is not possible to install a virus scanner on every device, iOT). Fortunately, Safeonweb receives information (from its partners) about viruses circulating in Belgium. In the Safeonweb application, it is possible to register your wifi network. If you do so, you will receive a warning (under the threats tab) when you have caught a virus.
 

More information about registering your WiFi network: https://www.safeonweb.be/index.php/en/safeonweb-app. It may well be that your computers are all healthy. Great news! In the application it says "no threat to this network". If you have caught a virus, you can use the name of the virus to look for treatments. 

If you also want to keep your computers healthy, I suggest the following tips.

1. Install an anti-virus scanner
2. Install the safeonweb application