Domain Name System (DNS): Untangling the Key Aspects

The most important things in life don’t always scream the loudest. Well, this is the case of the often overlooked Domain Name System (DNS). With the behind-the-scenes nature of DNS, many CISOs underestimate what criminals can do with it and focus on other areas of security.

Unfortunately, when they do so, they expose their systems to various high-impact crimes such as DNS hijacking, for instance. One prominent example of this is the infamous ongoing “Sea Turtle” campaign of espionage which has already compromised more than 40 organizations around the world.

So, as hackers get bolder and smarter by the day, it’s especially important for CISOs to pay extra attention to DNS. In this post, we’re going to delve into its functions and capabilities and talk about some of the best practices that experts can apply to make the most out of it.

What is DNS: A Quick Review

The domain name system is a shared directory capable of determining human-readable hostnames into machine-readable numbers and vice versa.

The process of DNS resolution begins when a hostname, for example, www.facebook.com, is converted into a distinct series of numbers, which in this case, is 66.220.144.0. Each time a user wants to visit a website, a translation needs to happen in order to locate the specified domain. This translation is performed by DNS servers.

DNS can be considered as a repository for important domain name information such as address records and Canonical Name Records (CNAME), Mail Exchanger Records (MX records), text record verification of domain ownership (TXT Records), sending verifications, and more.

The Role of DNS in Combating DNS Based Threats

DNS has been working for many years and is accessible to anyone with an agenda. Unfortunately, this means that cybercriminals can exploit it too for such malicious activities as the aforementioned DNS hijacking or DNS cache poisoning where perpetrators target gaps in the DNS to redirect Internet traffic towards counterfeit servers instead of the real ones.

The good news is that the prevalence of DNS can likewise be an ideal starting point to improve one’s cyber defense. Here are a few examples:

Spam identification — by analyzing the DNS data of email senders, spam can be filtered and separated while its sources are made known.

Spotting dangerous websites — a DNS Database Download service can help identify suspicious domains which are likely to serve as staging sites for cybercrime as well as expose domains and IP addresses associated with a malicious entity. The data feed files are downloadable in CSV format for easy integration. Here's an example.

Intrusion detection — harmful protocols that have infiltrated the company’s network can be detected by logging communications on DNS traffic before they can cause further damage.

How CISOs Can Leverage DNS for Better Cybersecurity

There are several ways CISOs can start utilizing the DNS system today. These include:

SIEM data enrichment — various SIEM, automation, and orchestration platforms can take advantage of the DNS data, for instance, by setting up a DNS firewall supplemented with actionable threat intelligence findings to prevent cyber breaches.

Assist during investigations — DNS history can be used to analyze leads based on the traces and signatures left behind by cybercriminals.

Use during cyber forensics analysis — Looking into the current and historical domain and IP data can bring about highly effective responses to post-breach attacks. For example, DNS records can be studied for suspicious changes that can be tied to threats.

Threat hunting — professionals can perform fact-based risk profile auditing on target domains, IP addresses, and other online assets by studying DNS traffic. Using the details obtained here, specialists can discover associations and collaborations among threat entities, therefore confirming or rejecting hypotheses.

In today’s ever-dangerous cybersecurity landscape, it’s imperative to check every nook and cranny to protect corporate networks. Paying attention to DNS and its capabilities can support these professionals in their goals by opening opportunities for better monitoring, identification, and isolation of malicious threats.