Some security products (like Windows Defender) as well as some VPN applications are known to modify the hosts file. Might be worth checking out.<p>Also see: <a href="http:&#x2F;&#x2F;security.stackexchange.com&#x2F;questions&#x2F;6883&#x2F;something-is-changing-my-hosts-file-without-asking" rel="nofollow">http:&#x2F;&#x2F;security.stackexchange.com&#x2F;questions&#x2F;6883&#x2F;something-i...</a>