What is a DNS Attack? 5 Practices to Prevent It

The Domain Name Server is a key component of the Internet. It was created as a system for converting alphabetical names into IP addresses so that users are able to access websites and send e-mails. DNS is structured as a tree-like infrastructure, with the highest-ranked domains, such as.com and.org, in the first level. General, usual domain names are found in the second-level nodes. Hosts are the ‘leaf’ nodes on this tree. DNS functions similarly to a database that is retrieved by millions of computer networks in order to determine which address is most likely to answer a user’s query.

In DNS attacks, hackers will occasionally target the servers that host the domain names. In other situations, these attackers will attempt to identify and steal sensitive information within the system itself.

Types of DNS Attack

DNS attacks have increased dramatically in the last few years. And this attack isn’t just aimed at small websites. Various popular websites, including Reddit, Spotify, and Twitter, have also made complaints about the lack of accessibility of their services to thousands of their users. As DNS attacks become more common, we must learn to recognize them so that we can better deal with the situation. 

Let’s take a look at the various types of DNS attacks.

Zero-day attack

A zero-day attack occurs when an attacker exploits a previously unknown weakness in the DNS server application or protocol stack.

Fast Flux DNS

To redirect DNS requests, hackers switch DNS data in and out at a specific rate. This technique also facilitates the attacker in detecting attacks.

DDoS (Distributed Denial of service)

The attacker has control over a large number of computers (hundreds or even thousands) in order to spread malware and overflow the victim’s computer with unneeded and overloading traffic. The systems will ultimately overload and crash because they will be unable to leverage the power required to handle the rigorous processing.

DNS spoofing

It is also known as DNS cache poisoning. It is a type of device security breach. Attackers or cybercriminals corrupt the entire DNS server by substituting the authorized IP address in the server’s memory with the fraudulent IP address. This allows them to redirect all traffic to a malicious website and collect vital information. This is one of the most common hacking techniques used by hackers to steal information. 

Because users enter the correct domain address into their browsers, they are unaware that they are visiting a bogus or rogue website. As a result, detecting this attack becomes difficult. Users may not be able to find this until the time to live (TTL) lapses. TTL, or time to live, is the amount of time it takes for the DNS resolver to recall the DNS query before it expires. The best way to prevent DNS cache poisoning threats is to clear the DNS cache on a regular basis.

How Does DNS Attack Work?

When users enter a domain name into a browser, the operating system’s ‘DNSresolver’ system searches for the IP address of that web domain.

The DNS resolver first searches its own local cache to see if it seems to have the IP address for that domain. If it cannot find it in the local database, it queries a DNS server to determine whether it has the correct IP address for that domain.

DNS servers operate in a loop, which means they can query each other to determine which DNS server has the correct IP address for the domain name. When the DNS resolver finds the IP address, it returns it to the requiring program. DNS also saves domain addresses for future use.

Despite the fact that the Domain Name System is quite powerful, it appears to be less concerned with security. Perhaps this is why we are seeing a variety of DNS attacks.

System administrators must take some precautions to reduce the possibility of DNS attacks. They can use an updated version of DNS software and redundant servers on a regular basis. To avoid security risks, users can replace their DNS cache on an individual level.

5 Practices to Prevent DNS Attack

Here are a few practices for protecting your organization from DNS attacks:

Keep DNS Resolver Secure and Private

Only allow internal network users to use the DNS resolver; never allow external users to do it. This can keep external actors from poisoning its cache.

Configure Your DNS to Protect Against Cache Poisoning

Set up security in your DNS software to protect your organization from cache poisoning. Outgoing requests can be made more variable to make it more difficult for threat actors to insert a fraudulent response and have it accepted. For example, instead of UDP port 53, try randomly selecting the query ID or using a random source port.

Maintain Your DNS Servers Securely

Authoritarian servers can be organized in-house, by a network operator, or with the assistance of a domain registrar. You can have complete control if you have the necessary knowledge and skills for in-house hosting. If you lack the necessary skills and scale, you may benefit from outsourcing this attribute.

Zone transfers should be limited.

DNS zone transfers are DNS zone copies. If your DNS zone transfer ends up in the hands of an attacker, it can provide them with a better understanding of the mechanism of your network. You can protect attackers from conducting zone transfers by heading into your DNS software’s configuration file and limiting zone transfers to specific IP addresses.

Refresh your DNS servers.

Cybercriminals love exploiting vulnerabilities in old software, so applying patches as soon as possible is critical. This is true for everyone, including those who operate their own nameservers. The most recent versions of software, such as Microsoft DNS and BIND, support security standards such as DNSSEC, which provides authentication and authorization integrity measures.

Final Thoughts

Due to the broad range of DNS attacks, it is not possible to go into detail about each important defense mechanism. Because each company has its own infrastructure, applications, and needs, it’s difficult to provide sound advice for every situation.