Introduction

The internet is a place of all kinds of dubious tactics that takes place. It is essential to be alert at all times to be protected from the type of scams that takes place in the multiple online platforms and websites that have been made to make our lives much more accessible. There are good and bad ways of making use of the internet; however, because of its easy accessibility to all, it has become easier for some attacks related to web servers and websites to be carried out even more smoothly than it did. DNS spoofing which stands for Domain name server, also known as DNS cache poisoning – is one of those attacks that have suddenly gained momentum in this space. 

  1. What is DNS Spoofing?
  2. DNS Spoofing Tool
  3. DNS Spoofing Example
  4. DNS Spoofing Prevention

1. What is DNS spoofing?

A DNS spoofing attack is defined as the kind, in which the hackers make use of altered forms of DNS data that are available. This kind of an initial step is taken in the initial stage of DNS poisoning attack so as to redirect all the online traffic that is present to an alternative fraudulent existence of a website, and it is made sure that this fake website resembles the intended destination, which is the initial original website in question.

The entire process of cache poisoning entails as such where false information is entered into the space allotted for DNS cache. The objective behind doing so, is so that all the queries that are sent to the DNS, sends back an incorrect response, and that would make the users opt for, or instead, they would be directed to the wrong websites, as was the intention behind this kind of a cyber-attack.

Now to understand better about what is DNS spoofing attack really, we need to first wrap our heads around how does it work?

There is something called the DNS revolvers which are very much needed to go ahead with this process – what they do is that they provide the clients with the IP addresses they are looking for. These IP addresses are associated with a particular domain name. Their aim is to purchase human-readable website addresses and then have them converted to machine-readable IP addresses – this is the primary role of a DNS resolver.

Hence because of this, when a user is attempting to get into a website, the concerned operating system sends an instant message to a DNS resolver. This is when the DNS revolver provides the IP address asked for, and the web browser reads this address and eventually initiates the website that is requested. DNS spoof all websites is the ultimate goal for these hackers.

Now while understanding a DNS spoofing meaning, it is essential you first understand all the triggering factors behind it.

Now, this DNS revolver does an exceptional job of saving all the responses that are directed towards IP address queries. This enables the DNS revolver to respond to questions much more quickly in the future. They do not need to get in touch with the multiple servers involved in an elaborate DNS resolution process. So these revolvers store the responses for as long a time as possible into their cache.

Now as per DNS spoofing definition – Attackers are fully equipped to poison the intended DNS caches by impersonating their targeted DNS name savers. They do this by sending a request to a particular DNS resolver, and then these attackers are the ones who forge an intended reply when a DNS resolver does its job by sending queries to a nameserver. This is absolutely possible when one intends to DNS spoof all websites as these DNS servers use UDP and not TCP. Also, with no verification for any kind of DNS information, this cache poisoning process becomes straightforward.

2. DNS Spoofing Tool

Now there are tools that are involved in carrying out this kind of cyber-attack. 

The two most important ones that you first need to know about are:

  1. Dnsspoof – The function of this tool is to navigate all the DNS requests to the fake local computer’s host file once it is created in the name of the phony website’s IP address.
  2. arpspoof – This tool is to issue a command for the IP address.

The most used and typical applications for this is the DNS spoofing kali. There are actually steps that are involved as well that clearly show how applications for the matter, such as DNS spoofing Kali Linux.

So the process would first require you to fire up the Kali. Once done, you are directed to click onto Applications which will lead you to Kali Linux. Then you click onto Sniffing in the window that opens, and the second last step is to select the option of – Network Sniffers. After this step by step guide is followed – the final step is to finally select dnsspoof. When you click onto dnsspoof – a terminal with a straightforward syntax opens on the screen, and this is how the attackers are now able to divert the online traffic to a fraudulent website. 

3. DNS Spoofing example

There are many DNS cache poisoning attack examples that one can be made aware of. 

The necessary process follows as such where an attacker is made to intercept a particular communication channel between an intended client and a server computer belonging to the targeted website – say in this case – www.estores.com with an IP address – (IP 192.168.2.200).

1. One of the most common tools used for this spoofing – arpspoof – which is used to dupe the client to think that the IP address is actually – 192.168.3.300) and it does the same with the server, where it is made to believe that the client’s IP address is also IP 192.168.3.300)

Now in an example like this, the situation that generally unfolds is where – 

2. The attacker makes use of the tool – arpspoof to issue a command for the IP address. This will lead to the modification of the IP addresses in the ARPS table making it evident that probably the attackers’ computer is that of the client

3. The tool is once again used by the attacker to make the client or user believe that the attacker’s machine itself is the server.

4. Next, a Linux command is issued by the attacker, where all the IP packets are sent to the perpetrator’s computer, anything that has been exchanged between the client and the server.

5. The host file of www.estores.com is made in the perpetrator’s computer where the attacker can map the activities on the original website in the local or fake IP that they have created.

6. The attacker now sets up a web server in the IP address of the local computer and creates a fake website where they would divert all the online traffic. 

7. The final tool used here – is the DNS spoof which enables this entire attack to take place by diverting all the DNS requests to the local computer’s host file. Hence the fake website is visible to its users, and malware gets installed in the computers of all these users.

This is one of the most well explained DNS cache poisoning example.

4. DNS spoofing prevention

Once the DNS poisoning definition and its functioning are made clear, it is essential to be aware of the possible solutions for DNS cache poisoning prevention.

There is something known as the Domain Name System Security Extensions, and it is one of the effective ways in which one can determine the authenticity and origin of DNS data Since earlier no such verification was possible, DNS poisoning had become so easy to be carried out.

DNSSEC makes use of some key cryptography to verify the origin and integrity of all the DNS cache data. It is not full proof yet, so there are still chances of such malicious attacks to take place, but it is a start.

Hence DNS poisoning check can be monitored now, but there is still a lot of progress that needs to be made in the prevention. This is one of the many cyber-attacks that hackers make use of, and it is essential that people are informed about such malicious attacks so that they do the needful of protecting their websites and not causing deceit to their users.

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