Secured DNS

The most common attacks
Like always, attackers will find several ways to attack and exploit servers like DNS. Here’s a list of a few of the most common ones and what happens during these attacks.

DNS Hijacking: When it comes to this attack, an attacker will redirect queries to a different domain server. How they do this is usually thanks to malware or an unauthorized mod of a DNS server. Even though this type of attack seems very similar to DNS spoofing, this is, in fact, a different type of attack because it explicitly targets DNS records of the website instead of the cache.

DNS spoofing: This type of attack and also be called cache poisoning. Fake DNS data is put into a DNS cache when this attack occurs. This results in returning the incorrect IP address for a domain. This means that instead of going to the correct website, traffic will be directed elsewhere, usually to a malicious replica of the site, and will gather information like login credentials.

DNS Tunneling: This attack will tunnel through DNS responses and queries using other protocols. SSH, HTTP, or SSH can be used to pass malware or stolen info into queries and is usually undetected by firewalls.

Phantom domain attack: This attack is similar to an NXDOMAIN attack. An attacker will set numerous phantom servers that can either respond slowly or not at all. This will hit a resolver with many requests to these domains, leading to slow performance.

NXDOMAIN attack: The attacker will ask for records that don’t exist, hoping to result in DoS for traffic. A sophisticated tool can generate subdomains automatically for every request. Also, an attacker can target someone to fill the cache with junk requests.

Domain lock-up attack: What happens here is that the attackers will set up resolvers and domains to create TCP connections with actually legitimate resolvers. When the attack occurs, and the resolvers send requests, they will be hit back with slow packets, limiting their resources.

Random Subdomain attack: The attacker will send DNS queries for a few nonexistent, random subdomains of one actual website. This attack aims to create DoS, making it almost impossible to look up the site. Also, the cache might get filled with bad requests, slowing down the response even more.

Botnet-based CPE attacks: CPE (Customer Premise Equipment) devices will carry out these attacks. Service providers will give their customers hardware like routers, modems, and cable boxes for use. Attackers can compromise the CPEs, and these devices will become a part of a botnet, which is used to perform subdomain attacks against a site or a domain.

DNS Security Extensions (DNSSEC)
This is a security protocol made to mitigate problems. DNS Security Extensions will protect you against any attacks by signing data digitally to help you make sure it is, in fact, valid. In order to do this securely, the signing must be done at every level of this process.

The previously mentioned signing process is pretty close to signing any legal document on paper with your pen. The person creates a unique signature that no one else can make, and an expert can verify whether the actual person signed that document or the signature was forged. The digital signature does the same thing by guaranteeing that the data hasn’t been tampered with.

Even though advanced security is better, DNS Security Extensions are made to be backward-compatible to make sure that traditional DNS still works properly. DNSSEC should be able to work with other security measures, including TLS-SSL, as a part of the security strategy for the Internet.

DNSSEC needs to create a child-parent train of trust that will go all the way to the root zone. This trust mustn’t be broken because the request will be vulnerable to any future attacks. The root zone needs to be verified to close the trust chain, which is a thing an actual person does.

How to protect yourself against other DNS-based attacks?
Operators of a DNS zone can go one step further and secure their servers even more. A simple strategy to prevent DDoS attacks is over-provisioning infrastructure. To simplify this, the more traffic your server can handle, the harder it is to harm it. Organizations can establish multiple redundant DNS servers to accomplish this. Also, they can use load balancing to send DNS requests to servers that are working when others aren’t. Another way to protect yourself is by using a DNS firewall.

DNS firewall
This is a tool that can provide multiple performance and security services for DNS servers. DNS firewall can be found between the site you are trying to reach and a user’s recursive resolver. Attackers who try to harm the server can be shut down thanks to the firewall that provides rate-limiting services. If the site encounters some problems or is the target of an attack, the firewall can keep the site up and running by serving responses directly from the cache. A firewall can also provide faster DNS lookups and smaller bandwidth costs.

DNS can be used as a security tool
DNS resolvers can provide security solutions for their users if configured accordingly. Content filtering is provided by some DNS resolvers, and what this does is basically block malware and spam. It also comes with botnet protection which will block all communication with botnets. Most of these resolvers are completely free to use, and users can decide to switch to one by simply changing their router’s settings. This might not be as easy for some users, but with a little help from your security provider, it can be done.

How to maximize DNS security?
OB-Tech cares about security very much and offers top-notch services that will maximize the security of your DNS servers. Some of the included services are DDoS mitigation, DNSSEC, and multi-DNS functionality. If you have additional questions about securing your servers and ensuring they work flawlessly or any other questions, feel free to contact our support team, which is available at all times.