Well I just finished reading this [1] and found it interesting. But most of all I found this part interesting, "The executable, named 'PayPal-2.5.200-MSWin32-x86-2005.exe', is a Trojan Horse which modifies the DNS server of the local workstation and then deletes itself."

Well here is my question [Hopefully this question doesn't sound to stupid ] : How can one prevent the DNS server from being modified to one that the attacker controls ?? Is there a program that can alert you to this change ??

[1] ]Phishing Alert / Malicious Code: PayPal Traffic Redirection