What You Need To Know About DNS Attacks And How To Mitigate Them

As a service that translates the domain name into an IP address, DNS or Domain Name Server is the cornerstone of how the internet functions. When a DNS server is unavailable, all the websites it supports and the majority of applications become inaccessible as well. Knowing how much of the modern business takes place on the internet, it’s easy to see how DNS attacks can significantly impact the functioning of a company. More than a third of cybercrime activities worldwide are targeting DNS servers and the average loss for the organizations per one such attack is close to $1 million. The main reason for this is a lack of preparedness against DNS threats which is why the strategy to mitigate them should be seriously considered in every company.

How do DNS Attacks Work?

When attacking DNS, threat actors use several different strategies and techniques. The most common and basic form of a DNS attack is DDoS or Distributed Denial of Service where attackers use multiple computers to hit DNS servers. Creating this type of DNS flood overloads servers with queries, occupying the resources and making the server unable to respond to legitimate requests. Another major type of threat is Domain Hijacking which involves unauthorized changes to a domain registrar account and redirecting the traffic to another (commonly malicious) location. One of the most frequent remote attacks methods is DNS Tunneling. This type of attack uses encoded data from other applications to take over DNS servers. This way, attackers can abuse the DNS to receive orders from another server or steal sensitive data. Finally, DNS spoofing or cache poisoning usually involves injecting malicious data into a DNS resolvers’ cache. This allows attackers to lead the legitimate traffic to their own servers and use it for stealing sensitive information or phishing scams.

What Makes DNS Vulnerable?

The necessity of 24/7 internet access means that DNS operations should never be disrupted, not even for security inspections, making them constantly exposed to security threats. In addition, DNS requests are usually not restricted, meaning that they can pass the security controls and open the door for threat actors to exploit the servers. This can lead to all sorts of issues. Internal DNS servers store the IP addresses and names for all their domains. This information is shared with anyone who puts in a request, creating a pathway for hackers to gather all the necessary data for internal reconnaissance. As DNS cache is not authoritative, it’s susceptible to manipulation and a “poisoned” server can lead other computers to suspicious destinations.

How Companies Can Mitigate DNS Attacks

How companies should respond to DNS attacks could easily be the critical question to their survival in the market. As with personal computers, the prevention starts with regular updates. Using the latest version of DNS software and operating system will often stop the attackers from exploiting potential vulnerabilities. Also, organizations should constantly monitor server traffic and log in incoming and outgoing queries. This helps detect anomalies and enables a timely reaction to a potential threat. Furthermore, a good idea is to install a comprehensive detection system that will prevent corporate computers from connecting to the internet unless the access is authorized. Protecting DNS servers also involves tightening admin access. Every change to DNS records and its infrastructure should require multi-factor authentication.

DNS Defense Should be a Priority

The threat of DNS attacks continues to grow every year as threat actors become more and more efficient in their activities and diversify their toolkits. In 2021, the number of attacks increased by a third, compared to the year before. Around 70% of organizations have experienced a DNS attack over the last year, and more than 60% of those attacked have faced multiple threats. With the increasing business dependence on internet access, the consequences of these attacks can be catastrophic, both financially and in terms of damage to brand and reputation.

Outages and poor DNS performance are something that no organization can afford. The threat should be acknowledged company-wide and sufficient resources for security purposes should be made available. Pushing the DNS defense to the top of the company’s security priorities can go a long way in protecting the business and sensitive information.