Pharming is a cyber attack intended to redirect a website's traffic to a fake site. Pharming can be conducted either by changing the hosts file on a victim's computer or by exploiting a vulnerability in DNS server software. DNS servers are computers responsible for resolving Internet names into their real IP addresses. Compromised DNS servers are sometimes referred to as "poisoned". Pharming requires unprotected access to target a computer, such as altering a customer's home computer, rather than a corporate business server.
The term "pharming" is based on the words "farming" and "phishing". Phishing is a type of social-engineering attack to obtain access credentials, such as user names and passwords. In recent years, both pharming and phishing have been used to gain information for online identity theft.
Pharming has become of major concern to businesses hosting ecommerce and online banking websites. Sophisticated measures known as anti-pharming are required to protect against this serious threat. Antivirus software and spyware removal software cannot protect against pharming.
An Example of Pharming
Suppose, for example, your friend played a trick on you, and changed a contact list on your mobile phone. Instead of a friend’s number which you have recorded in your phone as John, your pal changed it to Mary instead, without you being aware of this change. When you try to call John, you inadvertently call Mary instead. This is, generally speaking, how pharming attacks mess with their victim’s information.