March 13, 2023
DNS hijacking (also DNS poisoning or DNS redirecting) is a type of cyberattack in which a hacker tries to manipulate DNS requests to redirect users to malicious websites. DNS stands for Domain Name System. It is essentially the Internet phone book, translating your friendly web addresses, such as google.com, into an IP address understood by computers. Unfortunately, hackers were able to modify this translation service so that they would secretly send you to fake sites instead of real ones, and you might not even know it was happening.
This is called DNS hijacking and can be very dangerous, especially if you log into your bank or email account on a suspicious site. Hackers can see everything you type, so they can easily steal your passwords and other sensitive information. There have been many recent reports of DNS hijacking on significant sites such as Twitter and Facebook, so it's essential to be aware of the dangers and take precautions. One of the possible ways to protect yourself from DNS hijacking is to use VPN. This creates a protected tunnel between your device and the website you're visiting, so even if hackers manage to change your DNS settings, they can't see what you're doing.
How does DNS Hijacking work?
A DNS attack is an attempt to hijack information transferred between your computer and a website. When a user enters a human-friendly URL, such as "google.com", getting translated into a computer-friendly IP address. The latter looks like 126.96.36.199 for IPv4 or 2608:1140:210:1:278:1823:25c3:1915 for IPv6. Then, the IP address is exchanged through search servers, including recursive resolvers, the root name server, the top-level domain (TLD) server, and the authoritative name server, before the web page is found on the Internet. DNS hijacking is an attack on the Domain Name System (DNS). Sometimes it may be to make DNS unavailable for use, and other times it may be a covert way to redirect users to a malicious site. This is achieved either by poisoning the DNS server or by infecting the local machine with a virus that changes the DNS settings of the system. If someone successfully does this, you may end up on another site without even realizing it, or worse, be redirected to a rogue page that looks like the one you were looking for. Local DNS hijacking will reduce DNS redirects or DNS queries to increase efficiency.
Let's sum the risk of DNS hijacking:
- Redirects your web traffic to a fake page;
- This can lead to the theft of personal information such as passwords and credit card numbers;
- Sometimes it is used to spread malware;
- DNS attacks are often used in phishing schemes, where scammers try to get you to click on a fake link that takes you to a site that looks real;
- The risk is even higher if you visit websites that require you to log in, such as your bank account or email account;
- Even when your security solution mirrors the attack, the modified DNS settings can still mischief you;
Types of DNS attacks
We discussed DNS hijacking and how it can affect you. Now we want to elaborate a little more, talking specifically about the different types of attacks perpetrated on the domain name system. We'll go over some basics first, then we'll go into more detail on each kind for those interested. There are three main types of hacking attacks on DNS: cache poisoning, denial of service (DoS), and Man-In-The-Middle (MitM). Let's take a closer look at each.
- Cache poisoning attack - is an attack that takes advantage of DNS caching. When you request a website, your computer will store this information for a short time and then check to see if it can find the IP address of that website in its cache. If the website is not found, your computer will look up the domain on an external DNS server. Cache poisoning distorts this process, so you are redirected to a different web page than you intended.
- DoS attack is carried out by overloading a DNS server with requests, causing it to fail. This can be reached in several ways, including sending repeated requests for non-existent domain names or transmitting large zones that consume all available bandwidth in an overloaded service. DoS attacks are often used to extort money from businesses or organizations.
- MitM attack occurs when an attacker can intercept and alter traffic between two DNS servers. This can be done by setting up a fake DNS server that tricks both systems into thinking it is legitimate or taking advantage of a security vulnerability in one of the servers. This type of attack can be used to redirect traffic to malicious websites, steal sensitive information, or even shut down an entire website.
- Also, attackers hack DNS servers and reconfigure target websites so that their IP addresses point to malicious websites. Router DNS Hijack involves hacking DNS routers, changing settings, and affecting all users connected to that router. These are some of the many possible types of DNS hacks. By understanding how they work, you can better protect yourself against them. For example, local DNS settings will push DNS traffic to domain service providers.
How do I prevent DNS hijacking?
DNS hijacking is a serious security problem that can allow an attacker to control your website, email, or other online services. To stop or prevent DNS hijacking, it is recommended that you use reliable security software that protects against all kinds of threats.
Use a good firewall. While using a hardware firewall is best, you can at least enable your router's firewall if you don't have one. Also, do not use public wifi networks to share personal information, especially if you need to enter credentials.
Pay attention to the site's URL to ensure it is the site you want to visit. If any part of the address seems unfamiliar, close your browser and check your DNS settings. Phishing sites do not have a valid SSL (secure sockets layer) certificate. Ensure that your site has a valid SSL certificate, as indicated by the padlock icon in your browser's address bar. Never enter sensitive data (e.g., personal information, credit card details) into a web form on a site without a valid SSL certificate. Here are some tips on how to prevent DNS hijacking:
- Use a trusted DNS provider;
- Enable two-factor authentication in your account;
- Use a strong password and don't tell anyone;
- Install antivirus software and keep it up to date;
- Update the firmware of the router to the latest version;
- Disable remote administration;
- Use a firewall to protect your system and network;
- Always create a backup of your website and data in case of an attack.
This way, you can minimize all the risks of DNS hijacking. If you are already infected, it is better to delete the contents of the HOSTS file and reset it. After that, use antivirus, which will help you eliminate DNS Changers. Check to see if the DNS changer has changed your DNS. If so, you should change your DNS settings. You can check this automatically. Alternatively, you can check DNS manually. Start by checking the DNS mentioned in Router and then on the individual computers on your network.