Final answer:
A pharming attack typically utilizes DNS cache poisoning to redirect users to malicious websites. ARP spoofing is also an attack technique, but it doesn't specifically compromise DNS. Cross-site scripting and phishing are different types of security threats not involved in redirecting traffic via DNS.
Step-by-step explanation:
The pharming attack technique that is used to redirect legitimate web traffic to malicious websites is DNS cache poisoning. DNS cache poisoning involves corrupting the DNS cache with incorrect IP address information, which causes users who enter a legitimate website's URL to be redirected to a fraudulent site without their knowledge. This is how hackers lure internet users to illegitimate websites that may look entirely legitimate to the untrained eye.
ARP spoofing, another option listed, is a similar type of attack that works on local area networks by associating the attacker's MAC address with the IP address of a legitimate computer or server on the network. While ARP spoofing can be used to redirect traffic, it is more commonly associated with local network attacks and is not specifically aimed at corrupting DNS information.
The remaining techniques listed, cross-site scripting (XSS) and phishing, are also common security threats, but they do not typically involve redirection of web traffic through DNS compromise. XSS involves injecting malicious scripts into web pages viewed by other users, while phishing involves tricking individuals into providing sensitive information through the guise of a legitimate request.