DNS Security: What it is and How Does it Work?

Knowing and understanding the DNS Security or Domain Name System is important before diving into DNS security solutions and DNS protections. DNS is like a contact list or traditional phone directories on the Internet. To translate domain names into IP (internet protocol) addresses, DNS maintains a directory of various domain names. DNS addresses identify every device connected to the Internet, such as a laptop, PC, iPad, or mobile phone, including the hosting server.

Recent reports indicate that almost 90% of organizations suffered DNS attacks in 2021, with each attack costing about USD 950,000 on average. Additionally, a large number of these attacks affected Indian internet users. Thus, organizations must build secure DNS servers to ensure the highest DNS cyber security. Get Ethical Hacking training online and learn more about DNS security and attack. 

What is DNS Security?

Network attacks are increasingly targeting DNS. A DNS has the reputation of being one of the oldest and most relied-upon protocols on the Internet, making it a viable target for attackers. To ensure that DNS infrastructure can continue functioning quickly and reliably, it is important to use secure DNS tools to protect it against cyberattacks.

Why DNS Security is Important?

The DNS system has several design limitations, like many Internet protocols. Including spoofing, amplification, DoS (Denial of Service), or the interception of private information, these limitations, together with advancements in technology, make DNS servers vulnerable to a wide range of attacks. Therefore, organizations should handle DNS security issues carefully since it is integral to most internet requests.

Importance of DNS Security

Without DNS security, cybercriminals can easily identify security vulnerabilities and redirect a domain name to their desired location. It is unimaginable how uncomfortable it would be if we couldn’t access our company website because of an attack. The DNS threat can corrupt an online banking system and steal confidential consumer information. Thus, DNS Security is among the most critical cyber security tools, and organizations must take DNS security issues seriously.

How Does DNS Work?

Every device needs its IP address to route traffic to a connected device. The IP addresses resulting from IPv4 or IPv6 are translated to human-readable names using DNS. Similarly to a telephone number with a country code, area code, etc., the string of numbers consists of sections, including the network component, host and subnet.

Step 1: Obtaining Information About the Website

Enter the domain name into a web browser to visit a website. For instance, www.setyourwebpage.com. Upon entering the domain name, the computer will search its local DNS cache for its associated IP address. It will display websites if they are present locally. The computer will perform a DNS query if it doesn't already have the information.

Step 2: Obtain DNS Recursive Servers’ Contact Information

A computer queries another server if the information does not exist in its local cache. As with your computer, recursive DNS servers have their own local cache. Likely, common domain names are already in the cache of many ISPs who use the same recursive DNS servers. Cache-cached domains will end the query here and display the website.

Step 3: Locate Authoritative DNS Servers

DNS servers that recursively look for information elsewhere if they do not have it in their cache memory. Following that, the query is sent to the authoritative DNS servers in the chain. The search will continue until a nameserver is found for the domain. Records for domain names are stored in these authoritative name servers.

Step 4: Access DNS Record

A query to the authoritative name server will locate the IP address for www.setyourwebpage.com (A record). The authoritative name servers supply the A record to the Recursive DNS server. A local cache is then used to store the record. If another query is sent back to the recursive server, it can provide an answer to the A record for www.setyourwebpage.com. Every DNS record has an expiration date associated with it, which indicates when it will expire. After a certain period, some recursive DNS servers request updated records.

Step 5: Final Step in DNS Configuration

Your computer receives the A record from the Recursive DNS server. A local cache is then created on our computer and stored with the record. From the DNS record, it obtains the IP address and passes it on to our browser. Websites connected to A records will display this website using the web browser associated with the IP address. An entire lookup can be completed in milliseconds.

Types of DNS Security Threats

1. Typosquatting

Social engineering attacks such as typosquatting target internet users who type URLs incorrectly. For instance, the attacker requested to click on https://www.aplle.com/ instead of https://www.apple.com. When URLs misspell the original/authentic websites, users are typically tricked into visiting malicious websites. These fake sites trick users into entering sensitive information and have the potential to do significant damage to organizations by stealing sensitive information.

2. Distributed Denial of Service Attacks (DDoS)

Multiple connected online devices, collectively known as botnets, are used in DDoS attacks to overwhelm a target website.

3. DNS Cache Poisoning

Users are sent to the wrong website due to DNS cache poisoning, which creates incorrect DNS responses and inaccurate DNS cache entries. 

4. DNS Amplification

In DNS Amplification, attackers amplify their traffic using open DNS resolver functionality to dominate a target server or network with a large traffic volume, thereby rendering it inaccessible to the attacker. This is an effective distributed reflection-based DDoS (denial-of-service) attack.

Best Domain Name System (DNS) Security Tools

DNS security tools are designed to prevent cyber attacks by acting as an intermediary between the web browser and the websites the user is trying to access online. In addition to securing public DNS, its security tools eliminate botnet servers, filter content such as advertising or adult websites and fix typos in domain names. Below are the top six best DNS security tools to use:

1. Cisco Umbrella

Cisco Umbrella offers DNS security tools through its cloud server. A single DNS solution integrates multiple security functions, protecting devices, remote users, and distributed locations. It takes minutes to install the Cisco Umbrella DNS security tool and secure the user's data to max level. Cisco Umbrella reports provide information about the activity of each device or network within the system. 

2. TitanHQ WebTitan

In terms of protecting against web-based cyber threats such as malicious websites, malware, or ransomware, TitanHQ Web Filter stands out among DNS-based security solutions. Global enterprises trust TitanHQ Web Filter because its API set allows for advanced control over web and DNS filtering, allowing them to filter web traffic and DNS traffic. Additionally, the system provides real-time automated detection and blocking of malicious threats. 

3. Infoblox BloxOne Threat Defense

In addition to detecting risks, Infoblox BloxOne Threat Defense helps you prevent attacks early in their lifecycle. This solution enhances security stack effectiveness, safeguards digital operations, and lowers cybersecurity costs by integrating universal automation and ecosystems. Infoblox BloxOne Threat Defense includes DNS protection tools to help users protect their systems in hybrid workplaces with visibility, command, and automation.

4. F5 BIG-IP DNS

F5 BIG-IP DNS distributes DNS and application requests according to company regulations and data center and cloud service conditions, as well as the user's location and performance. As a complete proxy, F5 BIG-IP DNS can be configured across architectures and globally to supply global server load balancing for applications and DNS.

5. Palo Alto Networks DNS Security

The user can automatically prevent phishing attacks by enabling URL Filtering in Palo Alto Networks DNS security, including links in online ads, emails, SMS links, websites, HTTP-based command and control, and malicious sites. Palo Alto Networks DNS security is a great pick for SMEs (small-medium enterprises). 

6. Infoblox Advanced DNS Protection

The Infoblox ADP blocks various attacks, including DNS hijackings, volumetric attacks and NXDOMAINs. In addition to detecting and mitigating DNS attacks, The Infoblox ADP does not require security patches because it uses constantly updated threat intelligence.

What are Some Common Attacks Involving DNS?

1. DNS Spoofing/Cache Poisoning

The DNS cache poisoning method is also called DNS spoofing. The purpose of DNS spoofing is to redirect organic traffic from a legitimate server to a fake server by exploiting vulnerabilities in the DNS.  

2. DNS Tunnelling

In most organizations, DNS is used freely within and outside their networks since it is considered a trusted protocol. Cyber crooks exploit DNS for data exfiltration using malware that contains the data being exfiltrated in DNS requests. Attackers ensure that the data users are transmitting in the DNS response packet reaches a server controlled by them, not by the website owner.

3. DNS Hijacking

Users are fooled into believing they are connected to a legitimate domain when they are connected to a malicious one by DNS hijackers. DNS servers can be compromised to store incorrect data by using malicious or compromised DNS servers.

4. NXDOMAIN Attack

Clients are prevented from accessing the roadmap through the DNS NXDOMAIN flood attack. DNS servers are swamped with invalid or nonexistent requests when this attack occurs.

5. Phantom Domain Attack

Phantom domain attacks are types of DoS attacks that target authoritative nameservers. An attack is conducted by setting up several DNS servers that fail to respond to DNS requests or do so sluggishly, disrupting communication.

To find an IP address, a DNS server searches the addresses of other DNS servers connected to it; this process is known as recursive DNS. Attacks against phantom domains result in inefficient lookups or non-functional searches and waste of server resources.

When recursive DNS servers fully consume resources, they can cause serious performance problems by ignoring legitimate queries and focusing on non-responsive servers.

6. Random Subdomain Attack

Random subdomain attacks are similar to NXDOMAIN attacks except that they ask for nonexistent subdomains instead of nonexistent domains.

7. Domain Lock-up Attack

A DNS resolver is locked up by these attacks, as their name implies. This is accomplished by connecting to a resolver with TCP, and then allowing domains to send randomly generated junk packets, which overwhelm a resolver.

8. Botnet-based CPE Attack

These attacks are developed by exploiting devices such as modems, routers, cable boxes, etc., used as CPE (Customer Premise Equipment). The attackers compromise CPEs, and the devices are made part of a botnet that attacks one or more sites or domains at random.

Measures Against DNS Attacks

• One can protect private data with digital signatures and certificates. 
• One should do a DNS zone review regularly. It's easy to forget about checking domain names or subdomains that may run outdated software or expose unrestricted areas to attackers as time goes on. 
• To ensure that the A, CNAME, and MX records are accurate, reviewing all your zones, records, IPs, and SSL certificates is crucial. 
• Make sure to use the latest Hide BIND version software. Several features are available in BIND, including DNSSEC, DNSTAP, Scaleable Primary-Secondary Hierarchy, Minimal ANY Responses, and many more. Major DNS servers on the Internet use BIND software. 
• Maintain regular software check-ups and fix faulty bugs as soon as they arise. 
• Make backups of data on different servers; in case of corruption or loss on one server, other servers can restore the data.  
• Ensure the data centers are connected to various networks; it helps in reducing the risk of single-point failures. 
• Ensure that your DNS configuration is as secure as possible. The domain names that need to be resolved can be randomly cased, and one can randomly generate the query ID instead of the standard DNS port.

Best DNS Servers for Security

You can improve and use secure dynamic DNS by switching DNS providers. With so many things on the Internet involving DNS requests, choosing the fastest DNS directory across all your devices and securing public DNS will allow you to do almost everything faster. The top three recommended best DNS servers enhance your online security. 

1. Cloudflare DNS

There is no doubt that Cloudflare DNS is an excellent DNS protection service worldwide. Newly, Cloudfare DNS built 1.1.1.1, the fastest DNS service globally.

You cannot restrict what websites you visit with Cloudflare DNS protection, but your privacy comes first. Cloudflare does not log your DNS traffic or your IP address. The Cloudflare DNS filtering automatically deletes everything logged within 24 hours. Thus, Cloudfare DNS makes the best choice among many enterprises. Recently, in response to a massive DDoS attack against Minecraft, Cloudflare mitigated the damage. 

2. OpenDNS

A popular DNS server offers free, public, web-based DNS servers. Open DNS is a popular choice among many enterprises and is used by millions of people. Cisco has owned OpenDNS since 2016.

When it comes to protecting yourself from malicious attacks, OpenDNS is a reliable choice. You can speed up page loading by connecting to the nearest DNS server through anycast routing. In addition to high-speed internet transfer, OpenDNS also blocks phishing websites, filters adult web content, and records your online activity for a year.

OpenDNS offers three services in their Home package, two of which are free: OpenDNS Family Shield and OpenDNS Home. Aside from not recording internet activity history and not providing access to specific websites, it offers all the same features as the paid version.

3. Google Public DNS

The speed of Google DNS is its greatest advantage. In addition to global coverage, Google DNS is DNSSEC-encrypted as standard; it has load balancing and shared caching to improve cache hit rates. Using Google Public DNS will make your browsing experience faster and more secure, and you won’t be redirected. 

Key Tips for Maintaining DNS Security

1. DNS Security Extensions or DNSSEC

A pair of public keys is attached to every DNS zone and digital signatures are generated over DNS data using the owner’s key. Keeping this key material secured is the responsibility of the owner.

In DNSSEC, private key cryptography strengthens authentication through digital signatures. DNSSEC does not cryptographically sign DNS queries or responses but rather certificates that certify DNS data directly from the owner.

2. Encrypting Data

The encryption of data included in DNS requests and responses provides an enhanced level of security. A layer of security can be provided by encrypting data to prevent hackers from intercepting or inserting malware.

3. Implementing Secure DNS Configurations

DNS servers can be configured in a secret vault without being connected to other DNS servers inside an organization. As a result, two DNS servers cannot establish a connection with each other. It is, therefore, unlikely that other servers will be affected if one server is compromised.

Furthermore, limiting the amount of data that is stored on each server can be achieved with secure DNS configurations. An encrypted configuration helps prevent data from being compromised on a broader scale.

4. Running Regular System Updates

Updates to DNS servers are scheduled regularly. Keeping these updates up-to-date is crucial. These updates introduce new security protocols that enable the servers to identify and fix vulnerabilities before they impact other systems.

5. Strengthening Detection Protocols

Increased DNS activity about a particular domain from a single source is a critical warning sign of malicious activity. In addition, the number of domain names encountered by one source can increase when there is an attempt to enter the DNS server for spoofing. Thus, monitoring and preventing malware attacks requires strong detection protocols.

6. Security Training

DNS servers require robust security training, which is mandatory in most organizations today. Using safe practices when interacting with the internet becomes easier for users when they know the potential risks. One should include several key techniques in training: 

• Checking the SSL (Secure Sockets Layer) or TLS (Transport Layer Security certificates) of websites you access. 
• Be cautious when clicking unrecognized links. 
• Run security checks as soon as the system requests them. One should not delay the process. Delay makes the system more vulnerable. 

7. What is DNS over HTTPS?

DoH (Domain Name System (DNS) over HTTPS) encrypts DNS traffic within an HTTPS session by passing DNS requests through an encrypted HTTP session. By hiding DNS queries from view, DoH seeks to protect online privacy.

The DoH protocol works similarly to DNS, except requests are maintained by HTTPS sessions. This helps in reducing the amount of information passed between the user and the server. The encrypted data over HTTP protocol is supported by many web browsers, including Google Chrome, Microsoft Edge, and Mozilla Firefox, as part of their efforts to enhance data privacy and security. 

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DNS Protection Best Practices

DNS security practices are essential for all organizations due to DNS’s increasing importance in nearly all networked applications. A networked application can communicate easily with another with its help.

1. Enable DNS Logging

Businesses can protect their DNS servers from attackers by enabling log information for DNS activities. One can comprehensively track DNS events and activity using this strategy. 

2. Lock DNS Cache

If the DNS server receives a request, it usually caches that information for future use to answer the request quickly the next time. DNS caching, however, can be dangerous because attackers can alter the cached information. Preventing unauthorized changes to cached details requires locking them from unauthorized access. Administrators can decide when to update and scrutinize cached data. In DNS, the lookup information is only stored for a specified period based on the time-to-live setting. 

3. Filter DNS Requests to Block Malicious Domains

In addition to keeping malware off company networks and user devices, DNS filtering will protect corporate networks from spreading malicious software. Additionally, DNS filtering can block domains hosting forbidden or inappropriate content, but not necessarily those used for malware or phishing attacks.

4. Validate DNS Data Integrity with DNSSEC

DNSSEC is an extension of the Domain Name System that allows businesses to evaluate queries for authenticity and send only validated ones. Digitally signing DNS data is another way to ensure its integrity, which DNSSEC does.

The DNS server checks the signatures from DNSSEC when DNSSEC is installed. Validation and identification of the signature are required. DNSSEC provides integrity of shared data and its origin to protect companies from DNS spoofing and cache poisoning.

5. Configure Access Control Lists

The most reliable way to prevent attacks on primary DNS servers is to control access to them with an Access Control List. IT and system administrators should restrict access to the primary DNS server. Furthermore, the list must specify which servers are authorized to transfer zones. Attackers may push zone transfer queries via secondary DNS servers to gain access to the server. Cybercriminals cannot access zone information or data if they have an adequate ACL and zone transfer allocation.

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Conclusion

Unfathomable amounts of information can be found on the internet, but it has also brought cyber attackers into the picture. Whenever you browse online, one mistake can make you a victim of malware or phishing. To protect themselves against cybercrime, enterprises are increasingly using DNS security software. Learn cybersecurity protection techniques with KnowledgeHut Ethical Hacking training.