Major DNS Threats: Preventing DNS Hijacking and Leaks

Keeping your DNS safe is critical in today’s increasingly dangerous cyber environment

Preventing hackers from accessing your private data is a complicated task on its own. Data security and privacy are becoming more difficult in the face of cyberthreats such as WikiLeaks, WannaCry attack, Petya attack and the Equifax breach, all of which were exploited in a hacker attack.

Most fatal attacks can take down your entire website without the hacker accessing your system. A nasty entity could take advantage of the internet to divert your website visitors and the other incoming data before they reach your network. Here, the DNS system is key, as it is the first line of defense and plays a critical part in data security.

This article, you will find two prominent DNS threats and ways to prevent them.

What is DNS?

DNS is a kind of internet directory that delivers your device’s name to the universe. DNS request processing involves your browser, DNS server of your ISP or a private organization and the DNS server of the website or company you are visiting.

A DNS server encompasses all the domain names and their corresponding IP addresses. Whenever you enter a URL, your browser will first send the IP request to the DNS server, and the DNS server transmits back the corresponding URL IP to your device. For instance, if you enter the domain name, your system sends a request to the DNS server. The server instantly matches the corresponding IP address of this URL and directs your browser to the website.

In simple words, the DNS procedure results in translation of the domain names into IP addresses. The translation process is necessary to take an internet user to a webpage because the browser is unable to understand the alphabetic URL and can only process the numerical IP address.

DNS Hijacking

By overriding a computer’s TCP/IP settings, a hacker or malicious individual could initiate changes anywhere in between the DNS resolving chain—a process known as DNS hijacking. An attack such as DNS hijacking is organized through the use of fraudulent software or by altering a server’s DNS settings.

There are two major types of DNS hijacking:

  1. Injecting malware or DNS Trojan attack software in a system to deceive computers so they restrict the further translation of user-friendly domain names to the correct analogous IP address.
  2. Hacking and modifying a particular website to redirect visitors to a completely different website.

DNS hijacking is mainly done for profit. However, there are some other reasons.

ISP DNS Hijacking

Many internet providers use the DNS hijacking technique in the name of enhancing the customer experience. Most commonly, when you enter a URL that doesn’t exist or is no longer available, an ISP redirects you to a different website.

Following this practice, ISPs could gain more revenue because they own the alternate pages they display. However, such DNS hijacking also can be a threat to your privacy, as it provides the chance to exploit an unprotected DNS server.

DNS Hijacking for Phishing

Phishing is a very common threat to cybersecurity, and DNS hijacking is a prominent way of carrying out such an attack.

In a phishing attack when you search a URL, the hacker fraudulently takes you to an identical but different webpage without you being aware of it. This technique could be dreadfully harmful to a website as well as your privacy. For instance, if a hacker manages to redirect the visitors of a banking website to a fraudulent version, users could inadvertently give up their sensitive credentials.

Phishing also occurs frequently on free Wi-Fi networks. Wi-Fi phishing actually can occur on any Wi-Fi network, but free public Wi-Fis are more prone to it. Therefore, it’s best to avoid using free/public Wi-Fi if at all possible.

DNS Hijacking for Pharming

This tactic is much like the phishing one, but instead of redirecting the traffic to an identical platform, the hacker takes you to any other fake webpage that is not similar to your searched webpage.

The main purpose behind such DNS hijacking is to gain benefit through a malicious webpage, which is full of hacker-desired ads. Besides the annoyance, the ads displayed could inject malware into your system if you accidentally or knowingly on an infected ad.

How to Protect Against DNS Hijacking

The abundance and high risk of DNS hijacking is the best reason to implement proper privacy measures for your systems. It is vital for the organizations as well as for the individuals to keep appropriate DNS safety precautions.

Here are some important and easy-to-follow security measures to consider:

  • Use an appropriate DNS service other than the ISP DNS. Make sure the third-party DNS service (paid/free) is credible and regularly updates along with instant security patches.
  • Try not to browse shady websites, which display numerous popup ads from any fraudulent entity. Figuring out the suspicious element in these malicious ads is not difficult. Most malware-injected ads, videos or audio codecs have prominent grammatical mistakes and uneven sentences because most hackers focus on trapping individuals quickly instead of focusing on these details.
  • Using a VPN as a privacy tool could also be an effective way to prevent DNS hijacking and to minimize any other privacy threat.
  • Changing router passwords is also a way to minimize the DNS hijacking. Hackers looking to change your router settings would find it pretty easy if the router password is the default factory password.
  • Using antivirus software is also recommended by many privacy experts, as the chance of hacker invasion is lower with an updated and good antivirus program.

Above all, be aware of the issue. You should have decent knowledge about DNS hijacking. Also, you can use the ping utility to detect DNS hijacks easily. For example, enter a URL you are sure doesn’t exist, and if you successfully land on any webpage, there’s a good chance you’re a victim of DNS hijacking.

DNS Leak

As discussed above, DNS works as a correspondent between the internet and your device. However, with default DNS settings, the online activities of a user are visible to the ISP or anyone who has the legal or illegal access to the DNS server.

To eradicate this issue, many individuals use a VPN, which creates a safe and virtual connection over the internet. Adding a VPN to your system pushes all the DNS requests and data through a secure VPN tunnel.

Unfortunately, the VPN servers are not always 100 percent secure, and they could leak DNS requests. This is known as a DNS leak.

A DNS leak could expose the DNS query, including personal information such as the recipient’s address and sender’s address. Due to the routing of data through the unsecured path, the information eventually becomes visible to your internet service provider or accessible to any other entity.

Ways to Check DNS Leak

Checking for a DNS leak is a simple task, as there are many tools that one-click testing for DNS vulnerabilities.

First, you have to select an authentic and legitimate DNS leak tool, which normally has a DNS test capability on its website. (Try not to select a DNS tool offered by any VPN service because of possible conflicts of interest.) To run the test, connect via the VPN and then start the test to analyze your VPN performance.

If you see server information related to your ISP, then your system might be leaking DNS. Also, the lists, which are not directed under your VPN service, could signal a DNS leak.

How to Fix a DNS Leak

There are a couple of ways to prevent a DNS leak. The first step is to consider a legitimate VPN service with the DNS leak protection feature. However, you could manually change DCPH DNS server settings to set a static DNS server or third-party DNS from an authentic source.

With these altered settings, your information will not be exposed to your ISP, even if your DNS leaks.

Minimize DNS Threats with Proper Care

A small investment in both time and money could save you from a potential loss of assets including private data, user trust or the organization reputation. But the best way to mitigate risk is to stay informed and practice regular updates and security checkups.

Zehra Ali

Secure Guardrails