What is DNS tunneling?

Do you know how dangerous and damaging DNS tunneling could be for your organization? If not, no worries. In this article, we will explain that. In addition, we will give you more information about its purpose, how it functions, and the prevention methods. So, let’s not waste any more time and get into business.

Meaning of DNS tunneling

DNS tunneling is a malicious and complex attack. Its purpose is to send DNS requests to the attacker’s server, giving the attackers a covert conduit for command and control and a route for data espionage. The cybercriminals breach the target DNS server and remotely take over management using data payloads.

How does it function?

For internal employees to access external websites and outside users to locate their websites, businesses permit DNS traffic to get across their firewall.

What is Firewall monitoring?

This characteristic is exploited by DNS tunneling, which uses DNS requests to set up a command and control channel for malware. Outbound DNS traffic can exfiltrate sensitive data or deliver answers to the malware operator’s requests, whereas inbound DNS traffic might transmit commands to the malware. Because DNS is a fairly adaptable protocol, this works. Because DNS requests are made to seek website domain names, there aren’t many constraints on the information they can contain. These fields can be used to carry sensitive information because nearly anything can be used as a domain name. These queries are intended to be sent to DNS servers under the attacker’s control, enabling them to accept the requests and provide the necessary DNS answers.

To sum up the process in three steps, it looks lite this:

1. First, hackers control a domain that links to a server that has malware running on it.
2. The hacker uses a server that has been compromised with malware to look for the attacker-controlled domain.
3. The DNS resolver creates a tunnel between the attacker and their target as it routes the query, enabling them to gather information, take over the server remotely, or carry out other attacks.

Ways to protect your organization against DNS tunneling

Is defense against DNS tunneling attacks possible? Yes, it is the answer. How? We’ll examine the two primary approaches.

1. The first step is to put a firewall system in place. This may be the best method of protection against the DNS tunneling assault. Why? Because all unwanted communications can be instantly detected and stopped using this technology.
2. The second is to keep an eye on DNS traffic (DNS Monitoring). This is another clever tactic. Why? Because you’ll be able to keep an eye on DNS traffic and be informed of any activity that could be detrimental. This can help you lessen the risks connected with DNS tunneling.

Conclusion

Since DNS was originally designed for name resolution rather than data communication, it is frequently overlooked as a threat to malicious information exchange and data exfiltration. Because DNS is a well-established and trusted protocol, attackers know businesses rarely check DNS packets for malicious activity. As a result, DNS is less important, and most enterprises focus their resources on slicing up web or email traffic because that’s where they think attacks frequently happen. DNS tunneling must be generally found and prevented through continuous endpoint monitoring.