The Preferred DNS Server setting is for entering a specific (preferred) IP address
for a DNS Server which is commonly used in network (private/work/business) environments. However most Internet Service Provider (ISP) have their own caching DNS server to reduce network load. Please read How Domain Name Servers Work
More specifically, the DNS (Domain Name Service
) is a service that resides on a Server and communicates to client computers what the name is that associates with an IP address. The preferred DNS is where the client will look to first for the name resolution.
The IP address 18.104.22.168
resolves to NL-SOFTSOL (Soft Solutions Inc.) in the Netherlands.
Are you part of a network? Do you recognize Soft Solutions? That's why I said "It's possible that your ISP (Internet Service Provider) requires specific DNS settings here. Make sure you know if you need these settings or not BEFORE you make any changes or you may lose your Internet connection. If you're sure you do not need a specific DNS address, then you may proceed.
If not, then the setting was probably altered by malware. There are Trojan infections (DNSChanger
) which can change DNS settings and redirect your browser to their DNS Server or other wanted sites.
ZLOB Enters The Search Engine Market
...rogue DNS servers are part of click fraud and leakage of personal information...we discovered that this network is now targeting four of the most popular search engines. In a large scale click fraud scheme, the ZLOB gang appears to hijack search results and to replace sponsored links with DNS “tricks”.
Malware Silently Alters Wireless Router Settings
A new Trojan horse masquerading as a video "codec" required to view content on certain Web sites tries to change key settings on the victim's Internet router so that all of the victim's Web traffic is routed through servers controlled by the attackers...recent versions of the ubiquitous "Zlob" Trojan (also known as DNSChanger) will check to see if the victim uses a wireless or wired hardware router. If so, it tries to guess the password needed to administer the router by consulting a built-in list of default router username/password combinations. If successful, the malware alters the victim's domain name system (DNS) records so that all future traffic passes through the attacker's network first. DNS can be thought of as the Internet's phone book, translating human-friendly names like example.com into numeric addresses that are easier for networking equipment to handle.