Q: Why is it important to protect the hosts file on my Windows system and how can I easily do this?
A: If the hosts file is unprotected, malware (adware, viruses..) could modify it and insert redirects to perform phishing and hijacking attacks. Such an attack can for example redirect you to a malicious banking website whereby the URL and interface appear to be correct but under the hood the site could use malicious content that tries to collect your bank account credentials.
A very simple solution to help prevent unauthorized changes to the hosts file, is to mark it as read-only. To do so, navigate to the hosts file with Windows Explorer - the file is located in the %Systemdrive%\Windows\System32\drivers\etc folder - right-click the file, select Properties, check the Read-only Attribute, and click OK.