Most popular DNS attack types.

All types of cyberattacks are threats to take seriously. But DNS attacks directed to hit your DNS (domain name system) are like lethal RIP bullets impacting your system. Your online business can be fully damaged!

DNS cache poisoning.

DNS Cache Poisoning (DNS Spoofing) hits through the DNS resolver servers. They can temporarily save a copy of the DNS records related to domains in their cache memory. Those records get cached the time established in their time-to-live (TTL).

Criminals can access the records for altering them (poisoning them) to redirect your legit traffic to a dangerous destination. For instance, they can create an impersonation of your website to cheat your clients and get their sensitive data.

DNSSEC (domain name system security extensions) is very recommended as a defense. It adds cryptographic authentication by digitally signing records for DNS searches.

DDoS Amplification. 

The objective of this type of DNS attack is to increase the traffic to unmanageable levels. There can be different implementations, but frequently, it exploits UDP protocol to harm your DNS. Since UDP doesn’t verify, criminals send a DNS request to ask for the IP address and more DNS information (records) to ensure that the answer becomes uncommonly large. 

Besides, attackers can alter the requests for all those large answers to go directly to the target and to overwhelm it with all the answers it didn’t ask. The final result will be the painful downtime. 

Prevent! An Anycast network can help since such networks include an amount of DNS servers capable of filtering and managing the type of malicious traffic we just described. 

DNS man-in-the-middle attack.

This DNS attack belongs to the so-called hijacking attacks. Its purpose is to redirect legit traffic to malicious destinations. It targets DNS servers. Criminals intercept the communication taking place between a legit DNS server and a user. The user requests the IP address to reach a specific domain, but instead of getting the answer from a legit DNS server, it’s answered by a criminal in the middle. Therefore, the IP address received by the user is not from the place he or she wanted to visit but a different one instead. 

Prevention is crucial! You can start by encrypting the communication with your clients with a strong and efficient tool. Clients can also protect themselves by using a VPN (virtual personal network).

DNS Tunneling.

This DNS attack exploits the DNS to encode (tunnel) malware and other information in DNS requests and responses (client-server way). 

Shortly it operates like this. A criminal registers a domain and points its name server to the criminal’s server. In this last, a tunneling malware software is set up. Criminal infects a computer for it to send a request to a DNS resolver server. DNS requests can freely go in and out of firewalls because DNS is allowed. Here the danger starts. The resolver directs the request to the criminal’s server, and a connection between the target and the criminal gets established via the DNS resolver server. This hides and makes it hard to identify the criminal’s computer because the connection between target-criminal is not direct.

As the first step of prevention, install a DNS effective firewall that can identify intrusions, strange DNS requests, answers, and patterns.

Conclusion.

DNS attacks are real and very disruptive. Prevention involves not a single measure but a combination of them. Since DNS is a reliable system, many people don’t see the need to monitor it (its components) and can suffer from one of these DNS attack types. Big mistake! Don’t take its security for granted! Be safe!

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