How DNS Filtering Protects Your Business from Cyber Threats

by Contributing Author

Domain Name Systems or DNS Filtering is an integral part of the IT infrastructure of any business today. Businesses use DNS filtering to protect their network from malicious attacks and unauthorized access. According to the annual DNS threat report, 90% of businesses from all industries have faced DNS attacks per year.

With an average of $1.1 million damage cost per attack, these organizations have faced an average of 7.5 attacks each. DNS filtering is one of the new cybersecurity solutions adopted by businesses to cope with the ever-evolving challenges of cyber threats. In this article, we will understand what DNS really is and how DNS filtering services can protect your business from cyber threats.

Let’s begin!

Understanding the Basics of DNS

DNS is often referred to as the phonebook of the internet as it translates the domain names to IP addresses. If it was not for the DNS, users would have to memorize entire IP addresses to access information on the internet.

Here is how DNS works:

1. As the user types a domain into the browser, their device sends a DNS query to the DNS resolver, which is a specialized web server.
2. DNS resolver uses additional DNS servers or cache to match the domain name with the correct IP address.
3. The correct IP reply is sent back by the DNS resolver to the device.
4. The content opens when the device contacts the server using the IP address provided by the DNS resolver.

The Rising Cybersecurity Threats

DNS attacks are at the top, with over 90% of business organizations across industries being the target in the last year. There are several types of DNS attacks:

•  Cache poisoning
• DNS Flooding (TCP and UDP flooding)
• DNS Rebinding
• DNS Tunneling attack

Here is a look at how DNS filtering protects businesses from these cyber attacks.

How DNS Filtering Works: An Overview

DNS filtering is a process used by businesses to block out any malicious site and filter out inappropriate content. IT engineers and cybersecurity service providers specially configure the DNS resolvers to play the role of a filter. When a user tries to access a domain that is tracked in the blocklist, the DNS resolver refuses to resolve that query.

Businesses can configure their DNS resolvers to have an allowlist instead of a blocklist. The allowlist will only have the domains users are authorized to access. DNS filtering uses two ways to stop malicious attacks: by blocking domains and IP addresses.

DNS Filtering Blocklist

A blocklist contains all the domains or IP addresses deemed harmful by the business. There are two ways for DNS filtering service providers to prepare the blocklist; they can get access to it from the cybersecurity community and add to it as per their client’s requirements, or they can simply generate their own blocklist.

Moreover, DNS filtering can also blocklist web pages that run on malicious JavaScript. Domains that are not malware or phishing attacks can also be blocklisted for having inappropriate content or, if deemed forbidden by the company.

Lastly, DNS filtering can also switch the blocklist into an allowlist. The allowlist will only contain the domains and IP addresses that users are allowed to access; all other domains and IP addresses will be automatically blocked.

Key Benefits of Implementing DNS Filtering for Security

DNS filtering is essential in today’s world. With cybersecurity threats being more sophisticated than ever before, businesses cannot compromise on the security of their IT infrastructure. Here is a look at the key benefits of implementing DNS filtering:

Improved Security

With DNS filtering, malicious websites, malware domains, and phishing sites are all blocked. Not only does this enhance the overall security of the company, but it also protects the workers from cyber threats.

Protection Against Phishing Attacks

Whether hackers launch targeting campaigns or generic phishing schemes to attack your business, DNS filtering blocks them from gaining access to you with remarkable accuracy. Emails or texts sent as phishing attacks are blocked; any accidental click will not work.

Protection Against Ransomware

DNS filters have the capacity to block all malware, including those that encompass ransomware. Furthermore, it prevents the spread of the malware across the network.

Decreased Downtime

DNS filtering can also be used to block domains such as social media, streaming platforms, gambling, and other sites that are inappropriate for work. Block Listing these domains allows you to have employees focused at work, resulting in greater efficiency.

Blocking Prohibited Content

Those IP addresses and domains that are deemed inappropriate can also be blocked using DNS filtering. Companies can choose to only allow certain domains safe for work and block the rest.

DNS Filtering vs. Traditional Firewalls: What’s the Difference?

DNS filtering and traditional firewalls are two pillars of any organization’s IT infrastructure. Although both, in theory, provide protection to businesses against potential threats, they are different from each other. Below are the details regarding the difference between DNS filtering and traditional firewalls:

Aspect	DNS Filtering	Traditional Firewall
Focus	Controlling website access and content filtering through blocking Domains and IP addresses.	Blocking or allowing traffic based on a wide range of criteria, including IP addresses, ports, protocols, and more.
Mechanism	Works at the Domain Name System Level, intercepts domain queries through DNS resolvers and uses the predefined filtering rules to allow or block the queries.	Analyzes the entire network packets and makes decisions based on predefined rules based on the organization’s security policy.
Scope	Limited to website access and filtering content online	Handles several different types of network security and provides a comprehensive approach.

Best Practices for Setting Up DNS Filters in Your Organization

Having DNS filters in your business organization will improve your overall security. However, implementing them can be a challenge. Given below are the best practices for setting up DNS filters in your organization:

1. Make sure the DNS filters are highly available and redundant. Having at least 2 filters is essential for any business.
2. Hiding the DNS servers and DNS information from those users that do not need them. Only the highly confidential personnel of the business should have access to the primary DNS server.
3. Enabling DNS logging allows us to know if an unauthorized person is trying to access our servers.
4. Locking the DNS cache means attackers cannot alter the already stored information regarding the user’s queries.
5. Configuring the access control list allows only the IT administrators and system admins to access the primary DNS server.

Key Takeaways

In today’s business landscape, sophisticated cyber threats necessitate layered security solutions for effective protection and seamless operations. DNS filtering is an essential part of the digital security infrastructure of any business. It not only blocks all malicious websites but also ensures all the cyber threats, such as malware, ransomware, phishing attacks, and more, are filtered out before reaching the business infrastructure.