DNS Security

Most people use domain names to designate the websites they wish to visit when they use the Internet. Computers, on the other hand, utilize IP addresses to distinguish between various systems connected to the Internet and to transport traffic via it. The Domain Name System (DNS) is the mechanism that allows domain names to be used on the Internet.

DNS traffic is often permitted to pass easily via network barriers since it is widely trusted by enterprises. Cyber criminals, on the other hand, frequently target and misuse it. As a result, DNS security is an important part of network security.

The Role of DNS in Cyber-Attacks

DNS may be utilized in a variety of ways. Attacks on infrastructure are one type of threat:

DDoS (Distributed Denial of Service): DNS infrastructure is critical to the Internet’s operation. DDoS assaults on DNS can render websites unreachable by flooding networks with what appears to be genuine traffic, rendering the DNS servers that serve them unavailable. The 2016 DDoS assault against Dyn, in which an army of bots placed on Internet-connected webcams caused outages on numerous major websites, including Amazon, Netflix, Spotify, and Twitter, is a typical example of this.

DNS DDoS Amplifier: Because DNS employs UDP for transmission, an attacker may fake the source address of a DNS request and have the answer routed to any IP address they choose. DNS answers might sometimes be significantly bigger than the matching queries. DDoS attackers use these elements to intensify their assaults by submitting a modest request to a DNS server and then receiving a huge response from the DNS server.

Denial of Service (DoS) Assaults: In addition to network-based DDoS attacks, DoS attacks may also target DNS servers and their applications. These attacks are aimed at taking advantage of flaws in systems that prevent them from responding to valid queries.

DNS may be misused and utilized in cyber attacks as well. The following are some examples of DNS abuse:

DNS Hijacking: DNS Hijacking is any assault that deceives a user into believing they are connecting to a legal domain when they are connecting to a hostile domain. This can be done by tricking a DNS server into keeping inaccurate DNS data, or by employing a hacked or malicious DNS server (an attack called cache poisoning).

DNS Tunneling: Because DNS is a well-known protocol, most companies let it freely enter and exit their networks.

With malware whose DNS queries contain the data being exfiltrated, cybercriminals use DNS for data exfiltration. The attackers guarantee that the data reaches a server where it may be processed by them and a response is provided in the DNS response packet since the target DNS server is normally controlled by the owner of the target website.

DNS Security and Its Importance

DNS is an outdated protocol that was created without any built-in security. Several DNS security solutions have been developed, including:

Filtering by Reputation: Most malware, like any other Internet user, requires DNS inquiries to determine the IP addresses of the sites it visits. Organizations can utilize threat intelligence to block or divert DNS queries to known malicious domains, preventing users from visiting harmful sites or malware from interacting with its operator.

DNS Inspection: An intrusion prevention system (IPS) incorporated into a next-generation firewall can identify and prohibit the usage of DNS for data exfiltration (through DNS tunnelling) and other malicious actions (NGFW). This helps to prevent malware command and control and other attacks from using DNS.

What is DNS and how does it work

Simply said, the DNS converts a domain name (for example, www.example.com) into a machine-readable numerical IP address (192.168.1.1). You’ll need a specific Internet Protocol address to discover a certain device on the Internet, much like you’ll need a street address to identify someone’s residence.

As a result, when you visit a website, a translation between what you write in your browser’s address bar and the associated computer-friendly address is required. The page’s host reads the number 192.168.1.1 and returns the desired response when you type www.example.com. Your computer plays no other role in the DNS retrieval process except to make the initial request. After then, the task is routed to four different servers:

DNS recursor, which receives your queries and responds with further requests.

TLD-nameserver, the next stage in the translation process, and root nameserver, the initial step in translating the human-readable domain name It contains the last part of the hostname, namely the dotcom Authoritative nameserver, which is the final stage in the retrieval process. If it has the IP address on file, it will transmit it to the recursor, which will then show the user’s related webpage.

Protect the Protocol: DNSSEC is a protocol that encrypts DNS answers and incorporates authentication. Attackers can’t utilize DNS to redirect users to malicious sites since the authenticated answer can’t be faked or manipulated.

DNS over TLS (DoT) and DNS over HTTPS (DoH) provide a secure overlay to an unsafe protocol. Unlike standard DNS, this guarantees that queries are encrypted and authorized. A user can secure the privacy of DNS answers and prevent eavesdropping on their DNS requests by employing DoH and DoT. (Which reveals the sites that they are visiting).

Is DNS safe to use

The quick answer is no, but please allow me to elucidate on why this is true. It’s crucial to remember that cybersecurity risks did not exist when the DNS was created over four decades ago. By default, the Internet was much smaller and hence far more secure, leaving the system with certain architectural restrictions.

Furthermore, you should consider the fact that the Domain Name Systems architecture has been tinkered with over time. Multiple modifications to this framework were made, and some of them may not have been the best. Needless to say, this resulted in a slew of flaws.

Here are a few of the most prevalent methods that hackers can take advantage of the DNS:

DNS spoofing is when fake data infiltrates a DNS resolver’s cache. As a result, it’s often called cache poisoning.

DNS tunnelling, in which hackers utilize HTTP, SSH, or TCP protocols to sneak malware into a system unnoticed DNS hijacking, in which hackers send user requests to a malicious domain name server, rather than the cache, DNS hijacking

Man-in-the-middle attacks, in which malevolent third parties listen in on, and intrude on communicating two parties, posing as both to some extent.

NXDOMAIN attack, in which domains are bombarded with requests for records that do not exist, resulting in a denial of service.

How DNS-Layer Security Aids in the Prevention of Cyberattacks

Because DNS is used to enable all internet activity, simply monitoring DNS queries – and their consequent IP connections – may go a long way toward safeguarding your network. Having security measures in place to highlight unusual DNS behavior can help you detect malicious activity and compromised systems more accurately, increase security visibility, and safeguard your network.

If you want to take things a step further, you can engage with a secure DNS vendor to enable your network’s computers to use proprietary recursive DNS servers. Your provider will set up these servers to detect malicious DNS behavior and implement security mechanisms to prevent it. DNS-layer security is the first line of defense against attacks. After all, DNS is the initial step in establishing an Internet connection. The attack comes to a halt if a risky connection is stopped at the DNS layer.

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