All About DNS Spoofing

The internet has a significant role in our daily lives, and also, this is a place where we are concerned about security. We merely depend on website information that users can access through a Domain Name System (DNS). This DNS can be spoofed by hackers that can be redirected to fraudulent websites resulting in malware attacks and data loss. In this detailed blog, we will discuss DNS spoofing, how it works, methods of DNS spoofing, tools used, and tips to avoid DNS spoofing.

Table of Contents

What is DNS Spoofing?
How does DNS Spoofing work?
Methods of DNS Spoofing attack
DNS Spoofing Tools
DNS Spoofing Attack example
Risks of DNS Spoofing
How to prevent DNS Cache Spoofing and Poisoning?

What is DNS Spoofing?

Domain Name System (DNS) spoofing or poisoning is a cyberattack that exploits the DNS server and diverts the website traffic from legitimate servers. This process is intended to enter false information into the DNS cache. So the response to queries received by the website is replied to with false information and redirected to a fake website.

How does DNS Spoofing work?

A DNS resolver will save responses to IP address queries. As a result, the resolver can respond to future queries significantly faster without communicating with the several servers involved in traditional DNS resolution. DNS resolvers save responses in their cache until the IP addresses set time to live (TTL) in seconds for the expiration of cached records ranges between 60 to 86400.

DNS spoofing attack imitates the server destinations to redirect a domain’s traffic. The purpose of a DNS spoofing attack is to redirect the victim to malicious websites. Whereas DNS cache poisoning is the user-end method of DNS spoofing, in which the attackers inject a malicious DNS in the local DNS cache. When DNS finds the malicious path in the cache, it redirects users to that link. The DNS will recollect the fraudulent website if the problem gets resolved or ever occurs on the server-end side.

Methods of DNS Spoofing attack

There are various methods for DNS spoof attacks. The most commonly used methods are discussed below:

• DNS server espionage : The hacker changes the server’s configuration to redirect all users to the malicious website. Then, the IP request for the spoofed domain will result in a fake website after a fraudulent DNS entry is fed into the DNS server.

• Man-in-the-middle : The interception of communication between the DNS server and the user redirects to the malicious IP address. A tool injects malicious IP addresses for cache poisoning on local devices and server poisoning on the DNS server.

• DNS cache poisoning : DNS cache poisoning code can be seen in URLs sent through spam emails. Such spam emails make victims click on the provided URL, infecting their system. Users can be directed to this code through infographics and banner advertising in emails and fraudulent websites. The system shall be poisoned and will redirect to fraudulent websites spoofing the real thing.

DNS Spoofing Tools

In this evolving technology, advanced tools are used for this spoofing attack. The well-known tools are described below:

• dnsspoof: This tool is used to navigate the DNS request to a fake system host file when the website IP address is spoofed.
• arpspoof: This tool is used to specify the IP address in the command.

The DNS spoofing Kali Linux application is used for DNS spoofing attacks. The process in this application helps to redirect the website traffic to the fraudulent website through a dnsspoof syntax screen under the Network sniffer menu.

DNS Spoofing Attack example

An attacker (IP 192.168.3.300) encrypts a communication channel between a client (IP 192.168.1.100) and a server system connected to the website in a DNS cache poisoning attack (IP 192.168.2.200).

In this case, a tool (such as arpspoof) is used to mislead the client into assuming the server’s IP address is 192.168.3.300. Likewise, the server is conned into assuming that the client’s IP is also 192.168.3.300.

1. The attacker specifies the command using the arpspoof tool to modify the MAC addresses in the server’s ARP table, making it believe that the attacker’s system is a client’s system.
2. The attacker executes the following command using arpspoof, which informs the client that the perpetrator’s machine is the server.
3. The Linux command used by the attacker results in IP packets received by the client and the server being redirected to the perpetrator’s system.
4. The host file is created on the attacker’s local system, which maps the website to its local IP.
5. The attacker develops a fake website that looks like the original website by setting up a web server on the local system.

All DNS requests are forwarded to the attacker’s localhost file using a program (e.g., dnsspoof). As a result, visitors are shown a fake website, and malware is injected into their systems, where users interact with the fake website.

Risks of DNS Spoofing

The significant risks of DNS spoofing and poisoning are as follows:

• Censorship: DNS spoofing is mainly used to censor the internet, leads to DDoS attacks on web servers, and redirects to malicious websites.
• Data loss: As DNS spoofing redirects users to phishing websites, there would be a huge loss of data that dumps on spoofed websites.
• Halted security updates: The spoofed website does not perform any legitimate security updates, and there are chances to form an attack surface for additional threats.
• Malware attack: A huge sump of malicious downloads would affect the entire system and DNS after being spoofed.
• Recovery difficulties: Eliminating the marks obtained by DNS cache poisoning is difficult. The system will return to the spoofed site even after cleaning the server.

How to prevent DNS Cache Spoofing and Poisoning?

To prevent DNS spoofing and poisoning, one should implement strict protocols and protective tools. Some of the prevention tips are discussed below:

• DNS spoofing detection tools: Several detection spoofing programs, ARP spoofing, can detect and certify legitimate data.
• DNSSEC: Domain Name System Security Extension (DNSSEC) helps maintain authentic and spoof-free DNS.
• End-to-end encryption: If data provided for DNS requests and responses are encrypted, attackers would be unable to reproduce the unique security certificate for the legitimate website.
• Beware of unrecognized URLs: Think before clicking on a link received through email, text message, or social media.
• Use of VPN: Virtual Private Network (VPN) helps provide an encrypted tunnel for web traffic, encrypted requests, and private DNS servers.
• Regular flushing of DNS cache: Cleaning out the infected data to keep your system away from DNS cache poisoning.
• Regular scan for malware: Spoofed websites could deliver all types of malicious programs, so the routine scan for malware helps remove secondary infections.

Final Words

For a user, it is difficult to identify a spoofed website. Assuming it is a legitimate website, the user will continue to provide information to the website, leading to data theft. Securing your DNS and implementing the best practices would help avoid DNS spoofing. I hope you had great learning.

InfosecTrain is a globally recognized training and consulting company focusing on various Cybersecurity and IT security training and consulting services. It offers a CompTIA Network+ online training course that helps you to achieve proficiency in network security concepts.

AUTHOR
Emaliya Keerthana
Content Writer

“ Emaliya Keerthana working as a Content Writer at InfosecTrain. She likes to explore the latest technology. She writes on emerging IT-related topics and is passionate about sharing her thoughts through blogs. “