- September 20, 2021
The Domain Name Server (DNS) converts the domain names into IP addresses, allowing users to access websites. Targeting the server for their domain names and exploiting the vulnerabilities present in the DNS has always been a target of assailants. DNS attacks affect every industry differently. Surveys have shown that financial service firms suffer the most financially. The manufacturing industry took the longest time to mitigate the attack. The education industry and the telecom and media industry also suffered huge losses.
According to the 2020 Global DNS Threat Report by EfficientIP, 79% of the surveyed organizations suffered from DNS attacks, with $924,000 in worldwide cost. Moreover, per the report, North America is the most affected region by DNS attacks. It also reveals a dramatic change in the type of DNS attack, ranging from volumetric to low signal. Including stealth and more inadequate bandwidth tactics, cybercriminals are changing the threat landscape.
The impact of DNS attack on businesses
The advent of cloud-based DNS has disrupted the DNS landscape. Notably, the shift from traditional DNS to cloud-based brings flexibility and enhances DNS performance. However, this transition has led to many new attack vectors. Furthermore, with increasing dependency on the cloud, many business applications are hosted in hybrid-cloud environments, making them a lucrative target for cybercriminals.
Below are some of the common types of DNS attacks:
- Zero-day attack: With this tactic, the hackers exploit the security vulnerabilities present in the DNS server software or protocol stack.
- Distributed denial of service (DDoS): This form of attack involves the hacker using publicly accessible open DNS servers to overwhelm the targeted system with DNS response traffic. Unable to handle the intensive processing required for such a large amount of traffic, the system eventually overloads and crashes. Per Cisco Visual Networking Index research, the number of DDoS attacks will double by 2023.
- DNS reflection attack: The main objective of this attack is to exhaust the bandwidth of the targeted network. Using numerous distributed open resolver servers on the Internet and combining it with an amplification attack, the DNS reflection attack sends thousands of queries using the victim’s source address.
- DNS poisoning: DNS spoofing or DNS cache poisoning attacks introduce data into a DNS resolver’s cache. It causes the server to return an incorrect IP address for further requests and diverts the traffic to the attacker’s computer.
- Fast-flux DNS attack: Using the fast-flux DNS attack, the hackers constantly change the location-based data to hide their actual location and get more time to exploit the system. There are multiple variants of flux. For instance, a single flux changes only the address of the web server, while the double flux changes both the name and address of web and DNS servers.
The immediate result of the DNS attack is that the website shuts down and prevents any visitor from accessing the content. Any business that depends on web traffic for profit can face financial loss. Even if the system hasn’t shut down, any ongoing DNS attack would slow down the system and affect productivity with its massive traffic. With the website running slow, the DNS attack also affects the website’s search engine ranking.
Data breaches are common with cyberattacks—DNS attacks are no different. The company’s reputation can take a massive hit by losing valuable data, and customers may deem the organization unreliable and irresponsible. It is difficult for small and medium-sized businesses (SMBs) to recover and regain consumer trust after a cyberattack.
Best practices to prevent DNS attacks
Usability was the primary intent behind the robust design of the DNS system—not security. As a result, it’s an easy target for advanced attack mechanisms. Attackers take advantage of the back-and-forth communication between clients and servers. Stealing credentials and redirecting DNS records are some of the most common DNS attack strategies.
A recent advisory from the US National Security Agency has focused on the seriousness of DNS attacks and how DNS over HTTP or DOH protocol standards can help prevent attacks. Enterprises should disable encrypted DNS within their network. Continuing to use only the enterprise DNS service is safer.
Here are some of the best practices to prevent DNS attacks:
- First, all organizations should take control over their DNS traffic and privatize their DNS connections.
- It is necessary to add protective DNS filtering and Internet access controls. These block most of the unknown malicious requests, both from any network device or any user system.
- Implementing DNS security and strong endpoint protection is essential for safer internet usage.
- Domain owners and DNS services should migrate using the Domain Name System Security Extensions (DNSSEC).
- Organizations should administer a reliable Internet threat intelligence within a protective DNS security filtering service. It would help reduce internet connectivity risks for SMBs.
- Using external security devices and threat intelligence would provide near real-time threat feeds and secure devices from a wide range of attack vectors.
DNS attacks have become one of the most prominent threats to the digital ecosystem. Awareness is the first step in preventing any cyberattack. By understanding the system’s inbound traffic, organizations can recognize any kind of DNS attack and respond accordingly.
As technology evolves, so too do the attack vectors. While the DNS attacks are getting sophisticated, DNS security must also step up to tackle them effectively. Organizations must strengthen their cybersecurity measures and make them resilient against new forms of attacks.