What is DNS Hijacking?

DNS hijacking mostly occurs when DNS requests are incorrectly resolved, and redirect users to malicious websites. It is also known as DNS redirection. This happens when a hacker controls a DNS server and redirects traffic to a fake DNS server. The server then transforms a legitimate IP address into that of a fake malicious website.

What is DNS Hijacking?

DNS hijacking is used for phishing, to serve users statistics or advertisements, or to collect user information. Many Internet Service Providers (ISPs) also use DNS hijacking to monitor users' DNS requests, collect data, and show advertisements when they visit an unknown domain. Certain countries utilize DNS hijacking to restrict visitors by redirecting them to government-authorized websites. In any case, DNS hijacking attacks use significantly on DNS. Typically, during a DNS hijacking, attackers incorrectly resolve DNS requests received by users and redirect them to fake websites without the consumers' knowledge.

How Does a DNS Hijacking Attack Work?

When you enter a website URL into your browser, it will retrieve information for the webpage from your local browser cache (if you have recently visited the site) or send a DNS query to the name server (typically provided by a trustworthy Internet Service Provider).

The point of communication between your browser's DNS request and the name server's answer is the most vulnerable to attack since it is not encrypted. At this stage, hackers intercept the query and reroute the user to one of their malicious websites for extortion.

How To Detect DNS Hijacking?

• Check your router: Digital router checker services use a dependable DNS resolver to check whether you use an authorized DNS server. Alternatively, you can go to your router's admin page online and verify the DNS settings.
• Examine your host file: Your computer's operating system uses the host file to map IP addresses to domain names before querying DNS servers. If your host file is modified, with an unfamiliar IP address, it could indicate a DNS hijack.
• Ping command test: A ping command effectively checks to see if an IP address exists. If your browser is pinging a non-existent IP address and still resolving, your DNS has likely been hacked. This can be done on both Mac and Windows.

Redirection vs DNS spoofing attack

Redirection is achieved by spoofing DNS. For example, attackers can compromise a DNS server, allowing them to "spoof" legitimate websites and redirect users to malicious websites.

DNS spoofing is another way without using DNS hijacking (physically taking over DNS settings). DNS servers, routers, and PCs save DNS records. Attackers can "poison" the DNS cache by inserting a forged DNS entry with another IP address for the same domain name. The DNS server resolves the domain to the spoofed website until the cache is refreshed.

Why are DNSs Hijacked?

A DNS can be hacked for a variety of reasons. The hijacker may utilize it for pharming, which is the display of advertisements to users to make cash, or phishing, which is the redirection of users to a false version of your website to steal data or login information.

Domain redirection is also used by Internet Service Providers (ISPs) to manage users' DNS searches to collect data. Other groups utilize domain hijacking to block content or divert people to alternate websites.

Types of DNS Hijacking

• Rogue DNS Server: An attacker can hack a DNS server and change DNS records to redirect DNS requests to malicious websites.
• Man-in-the-middle: Man-in-the-middle DNS attacks occur when attackers intercept communication between a user and a DNS server and provide alternate destination IP addresses that link to malicious sites.
• Router DNS hijack: Many routers contain default passwords or firmware vulnerabilities. Attackers can take control of a router and also change the DNS settings, which can impact all users connected to it.
• Local DNS hijack: Local DNS hijack occurs when attackers install Trojan software on a user's computer and modify the local DNS settings, redirecting the user to hostile websites.

Prevention Against DNS Hijacking

• Install firewalls around DNS resolvers: DNS resolvers are essential to every DNS, and attackers install counterfeit resolvers in a DNS to counter legitimate resolvers during a DNS hijacking attack, your IT team must protect your legitimate resolvers with a firewall to shut down any unknown resolvers. This prevents external access and secures your DNS.
• Improve Name Server Access Restrictions: An attacker can be within your business, your IT staff must implement a physical security system and multi-factor authentication access to reduce the risk of DNS hijack.

• Separately run Resolvers and Authoritative Name Server: Running both on the same server puts your DNS at risk of DNS hijacking because the attack on one also affects the other.

• Fix known domain bugs immediately: Perpetrators of DNS hijacking know that domain vulnerabilities occasionally occur, and they use these flaws to launch DNS hijacking attacks. As a result, your IT professionals must check your DNS for flaws regularly and immediately fix such bugs.

Conclusion

DNS hijacking is the internet-disrupting process to the resolution of Domain Name System (DNS) queries. This can be achieved by using malware to override a computer's TCP/IP configuration and point it to a rogue DNS server operated by an attacker.