Boncuk, this isn't a new threat, DNS hacks have been around for a LONG time, and this isn't even one of them. If the proxy settings of the browser have been altered then it was most likely from already running a trogan/virus that initiated the new proxy settings.
All this tool tells you is if you've already done something you shouldn't have.
True DNS hacks occur at the server level, and there is nothing the end user can do to prevent this from happening, although SSL will fail in such situations generally. It's a hot button issue right now because of the international nature of the Internet and how to secure DNS namespace in the first place without individual groups gaining control or being able to redirect traffic illicitly.