Domain Name Server (DNS) hijacking, also known as DNS redirection, is a form of cyber attack in which an attacker diverts DNS queries to direct users to malicious or unintended websites. DNS is a critical component of the internet infrastructure, translating human-readable domain names into IP addresses that computers use to communicate. By manipulating DNS responses, attackers can control where a user is directed when they enter a website address in their browser.
There are several methods attackers use to execute DNS hijacking. One common approach is to install malware on a user’s computer, which modifies the local DNS settings to point to a malicious DNS server controlled by the attacker. Alternatively, attackers may target routers, either by exploiting vulnerabilities or using default credentials to take control and alter DNS settings. In some cases, attackers may intercept or hack DNS communication between a user’s device and the DNS server to alter the responses.
DNS hijacking has various malicious applications, including pharming and phishing. In pharming attacks, users are redirected to fraudulent websites that display unwanted ads, generating revenue for the attacker. In phishing attacks, users are led to counterfeit versions of legitimate sites, where their sensitive information, such as login credentials or financial data, can be stolen.
Beyond individual attackers, DNS hijacking is also employed by some Internet Service Providers (ISPs) and governments for different purposes. ISPs may use DNS hijacking to redirect users’ DNS requests to collect statistics or display ads when an unknown domain is accessed. Governments may utilize this technique for censorship, redirecting users from prohibited websites to government-approved pages.
To protect against DNS hijacking, users and organizations can implement security measures such as using secure and reputable DNS servers, regularly updating router firmware, employing network security solutions like firewalls and intrusion detection systems, and educating users about the risks of malicious links and downloads.