DNS attacks are particularly dangerous, since they are often carried out to steal sensitive data. It is indeed estimated that 91% of malware are using DNS services to build attacks. But traditional protection systems are usually defenseless against these attacks. So, what is a DNS firewall and why should you choose one?

Different types of DNS attacks

There exist a slew of DNS attacks (data exfiltration, zero-day, volumetric and stealth attacks…). In these types of attacks, hackers try to change the actual settings of the DNS in order to redirect the request to another server to steal information from customers. All of them are quite complex and are carried out by cyber-criminals.


Some of these attacks are even used to distract companies while hackers carry out another, more significant attack or steal data. DDoS attacks are one of the most common ones. They consist in flooding taking control of DNS servers in order to disrupt a service and so the server will stop responding.alter and change their configuration.


DNS attacks include for instance cachesh-poisoning, also called DNS poisoning or spoofing. It is an attack in which the hacker replaces a legitimate IP address with that of another in order to redirect the traffic towards a fake website. The attacker can then collect information, or simply distract a company to perform another attack.


Another well-known attack is called zero-day attack; it consists in exploiting the flaws and vulnerabilities in the DNS in order to affect programmes and data. This type of attack occurs before a developer has the opportunity to repair a breach. The attacker exploits this breach, and his attack is rarely discovered quickly. It often takes months, sometimes years before this vulnerability is known. So, what is a DNS firewall and would it protect me against these attacks?  

What is a DNS Firewall?


The truth is, traditional firewalls and antivirus cannot offer a suitable protection for your DNS. You may therefore wonder: ‘what is a DNS firewall and why choosing one?’ Actually, there are parameters that companies can implement in their DNS and various systems available to enterprises to provide intrusion detection of these DNS attacks.

There are products which allow companies to secure DNS from external and internal malicious presence, in order to see malware trying to communicate from outside. DNS firewalls are configured to allow queries to pass through and stop initial infection. Read more on


On the one hand, they prevent connected devices from being infected and neutralise (or redirect) malicious queries. Other firewalls can offer other features, such as an up-to-date list of malicious IP addresses, domains, URL or name servers. They offer the right layer of defense which monitors and analyses traffic continually. Some of them even evolve with malicious attacks and are always updated to keep in pace with malicious IPs.

DNS requires defense in-depth strategy. DNS attacks interrupt business activity and damage brand reputation. Firewalls protect internet users and infrastructures against cyber-attacks, especially DNS malware. By asking the questions: ‘what is a DNS firewall?’ and ‘why would it be beneficial’ for my business?’, you already are heading in the right direction to protect it.