Domain Name Server (DNS) spoofing (a.k.a. DNS cache poisoning) is an attack where modified DNS records are used to redirect online traffic to a fake website such as a target site.
Once they do, users are instructed to log in (what they believe to be) into their account, giving the perpetrator the opportunity to steal their access information and other sensitive information. In addition, a malicious website is often used to install worms or viruses on a user’s computer, giving the perpetrator long-term access to and retaining data.
Methods for performing DNS spoofing attacks include:
- Man in the middle (MITM) – Interaction between users and the DNS server to redirect users to a different / malicious IP address.
- DNS server compromise – Direct DNS server hijacking, designed to recover malicious IP address.
DNS server compromise attack.
What Is DNS Spoofing?
DNS spoofing is a cyber-attack in which fake data is introduced into the DNS resolver’s cache, which causes the name server to return an incorrect IP address. In other words, these types of attacks exploit vulnerabilities in domain name servers and redirect traffic towards illegitimate websites.
When a recursive resolver sends a request to an authoritative name server, the resolver has no means of checking the response’s validity. The best the resolver can do is check if the response seems to come from the same IP address where the resolver sent the query in the first place. But relying on the source IP address of response is never a good idea since the source IP address of a DNS response packet can be easily spoofed.
Security-wise, due to the faulty design of the DNS, a resolver can’t identify a fake response to one of its queries. This means cybercriminals could easily pose as the authoritative server that was originally queried by the resolver, spoofing a response that seems to come from that authoritative server.
In a nutshell, an attacker could redirect a user to a malicious site without the user noticing it.
DNS Spoofing Methods
A DNS spoofing attack can occur under many guises. The most widely spread techniques used by hackers for this are DNS hijacking, cache poisoning, and man-in-the-middle (MITM) attacks. Perpetrators can use one of these methods, or a combination of them to achieve their nefarious goals. Let’s have a quick look at how each tactic works.
Also known as DNS redirection, DNS hijacking is a type of spoofing attack in which a user’s query is resolved improperly to redirect them to a malicious site instead of their target destination. Cybercriminals use various tactics to achieve this, either taking over routers, intercepting DNS communications, or deploying malware on the target’s endpoints.
In the case of cache poisoning, cyberattackers utilize modified DNS records to redirect online traffic to a malicious website that is designed to resemble the user’s intended query. This technique is usually employed to steal login credentials, as targets are immediately prompted to login into the fraudulent page.
DNS spoofing can also act as a type of man-in-the-middle attack, where a malicious actor intercepts a DNS query and returns a duplicitous page instead of the real thing. Besides directing potential victims to a phony site that is designed to replicate the user’s intended destination, hackers attempting a MITM attack sometimes simply relay the traffic of the real website and steal your information silently, in the background.
How DNS Spoofing Works
As I mentioned above, DNS spoofing comes with a few different methods which hackers can use independently or in tandem. Regardless of their MO, however, an attack of this sort will always have three essential steps – recon, access, and attack. Here’s a breakdown of what happens at each point in the operation.
Definition of DNS Spoofing and Poisoning
Domain Name System (DNS) Poisoning and spoofing are types of cyber attacks that exploit DNS server vulnerabilities to divert traffic from legitimate servers to fake ones. You need to know exactly how it works to protect yourself.
DNS spoofing and by extension, DNS cache poisoning is among the most deceptive online threats. Without understanding how the Internet connects you to websites, you may be deceived into thinking that the website itself is hacked. In some cases, it may be your device. Worse, cybersecurity suits can only stop some DNS spoof-related threats.
What is DNS and What is a DNS server?
You may be wondering, “What is DNS?” Again, DNS stands for “domain name system.” But before we define DNS servers, it is important to specify the terms involved in this article.
An Internet Protocol (IP) address is the ID name of a unit of numeric characters for each computer and a separate server. These IDs are the computers they use to find and “talk” to each other.
A domain name is a text word used by people to remember, identify, and link to specific web servers. For example, a domain like “www.example.com” is used as an easy way to identify the target server ID – i.e. IP address.
A domain name (DNS) system is used to translate a domain into a corresponding IP address.
Domain name system servers (DNS servers) are a set of four types of servers that include the DNS lookup process. Includes resolving name server, root name servers, high-level domain servers (TLD), and authorized name servers. For simplicity, we will only specify details on the solution server.
Resolving a name server (or duplicate solver) is the translating part of the DNS detection process that resides in your operating system. Designed to query – i.e. query – a series of web servers for a specific IP address for a domain name.
Now that we have developed a DNS definition and a common DNS understanding, we can test how DNS lookup works.
How DNS Lookup Works
If you are searching for a website by domain name, here is how DNS lookup works
- Your web browser and application (OS) are trying to remember the IP address attached to the domain name. If previously visited, the IP address may be recalled from the computer’s internal storage, or from the memory.
- The process continues if no party knows where the IP address is going.
- The OS asks for a resolving name server for the IP address. This query begins a search with a series of servers to find the same domain IP.
- Finally, the solution will find and bring the IP address to the OS, which redirects it to the web browser.
The DNS monitoring process is an important framework used by the entire Internet. Unfortunately, criminals can misuse DNS vulnerabilities which means you will need to be aware of possible redirections. To help you, let’s explain what DNS spoofing is and how it works.
Here’s how DNS Cache Poisoning and Spoofing Works
With regard to DNS, the main threats are doubled:
- DNS spoofing is a result of threats that mimic server locations to redirect domain traffic. Unscrupulous victims end up on malicious websites, which is the result of various DNS spoofing attacks.
- DNS cache poisoning is a user-only way of DNS spoofing, in which your system inserts a fake IP address into your local memory.
Methods for DNS Spoofing Attacks or Cache Poisoning Attacks
Among the various types of DNS spoof attacks, here are some of the most common:
Man-in-the-middle duping: When the attacker tramples between your web browser and the DNS server to infect both. The tool is used to simulate cache poisoning on your local device, as well as server toxins on the DNS server. The result is redirecting to a malicious site hosted on the attacker’s local server itself.
DNS Server hijacker: The hacker redesigns the server directly to target all the requesting users to the malicious website. If a fake DNS installation is installed on a DNS server, any IP request for a corrupt domain will result in a fake site.
DNS cache poison by spam: DNS cache code is usually found in URLs sent by spam emails. These emails attempt to intimidate users into clicking on a given URL, which infects their computer. Banner ads and images – both on untrusted emails and websites – can also direct users to this code. If it is poisoned, your computer will take you to fake fake websites to make it look real. This is where the real threats are introduced to your devices.
Risks of DNS Poisoning and Spoofing
Here are common risks of DNS poisoning and spoofing:
- Data theft
- Malware infection
- Halted security updates
DNS spoofing poses several risks, each putting your devices and personal data in harm’s way.
Data theft can be of great benefit to DNS spoof attackers. Redirecting will be criminal websites for stealing sensitive information designed to collect your information.
Infection with malware is another common risk with DNS spoofing. By redirecting you, your destination may end up being a site full of malicious downloads. Driving download is an easy way to make your system automatically infected. Finally if you do not use internet security, you run the risk of such things as spyware, keyloggers or worms.
Censorship is a very common risk in some parts of the world. For example, China uses DNS modification to ensure that all websites viewed within the country are authorized. This national level block, called the Great Firewall, is just one example of how powerful DNS spoofing can be.
Specifically, removing toxins from the DNS repository is difficult. Since cleaning the infected server does not remove the problem desktop or mobile device, the device will return to the infected site. In addition, clean desktops connected to an infected server will also be compromised.