What technique is commonly used in a pharming attack?

In a pharming attack, the technique primarily involves exploiting vulnerabilities in the DNS (Domain Name System) or DHCP (Dynamic Host Configuration Protocol) to redirect users attempting to visit a legitimate website to a malicious one. This is often accomplished by manipulating DNS settings to point to fraudulent IP addresses. By exploiting DHCP servers, an attacker can deliver the IP address of compromised or poisoned DNS servers to users on the network. This process allows attackers to intercept and redirect traffic seamlessly, making it difficult for users to detect that they are being directed to a malicious site rather than the intended legitimate site.

This technique ensures that even if users type in the correct URL, they can still end up at a site controlled by the attacker without their knowledge, thereby compromising sensitive information such as usernames, passwords, and other personal data. The focus on exploiting DHCP servers emphasizes the systemic nature of the pharming attack, relying on underlying network configurations rather than direct manipulation of individual computers.