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Small business operating with DNS filtering services.

Doman name service filtering, shortened to DNS filtering, is a DNS layer security service that blocks access to suspicious domains or those known to be malicious This service helps prevent users on your network from accessing websites that are known to be dangerous, whether they are aware of the validity of the link they are clicking or not. Additionally, malware attacks that require accessing C2 servers or other outside resources can be stopped as soon as they try to access the malicious domain needed for the attack. DNS filtering is one of the key security features included in DNS layer security, and here are some of the essentials you need to know about it!

DNS Filtering Functionality

DNS filtering can deem a website malicious or suspicious and block users from accessing it in a few ways. First, a worthwhile DNS filtering service will have a database of known domains that are known to be actively harmful and immediately prevent access to these sites. Filtering services can also actively crawl a webpage before a user is connected to it to make a determination on its safety in real time. If the filtering service determines a connection to be malicious, then the user will be sent to a page outlining the reason for the redirection. DNS filtering can also be used to block specific types of content, such as elicit content or material not suitable for work.

Protecting SMBs

Aside from blocking websites that employees may go to accidentally on their own, DNS filtering can help prevent attacks that specifically target a small or medium business. If an employee falls for a phishing attack, a filtering service can prevent that user from accessing the malicious website, which prevents them losing their credentials no matter how convincing the phishing site might be. Phantom domains, redirection attacks, and malware or ransomware attacks that require a connection to malicious domains can also be prevented with DNS filtering, which helps small and medium businesses prevent credential theft, data loss, and other threats while employees go about their day-to-day work.

Real World Example

End-users will not need to directly interact with DNS filtering services while it protects the business’ network. For example, an employee could receive a malicious email that contains an attachment that deploys malware on their computer. If the email disguises itself as an invoice or other important correspondence, then the employee may download it and have their machine infected with malware. The malware, once launched on the machine, will try to reach out to a C2 server and download a payload to act on the network. However, with DNS filtering, that connection won’t be made, and the IT department will be alerted to the security breach.


DNS filtering acts as a strong defense against malicious attacks that require a connection to resources outside of a business’ network, and this can make it a valuable tool when hackers do make it in. By utilizing a filtering service and other DNS layer security services, a small or medium business can improve its cybersecurity posture and become more resilient to attacks. Our security experts here at Robinett Consulting can help your SMB decide how DNS filtering and other security services can work together to help keep your business running securely!

Robinett Consulting

Author Robinett Consulting

At Robinett Consulting, we are your consultative partner who strives to grow your business and have technology truly enabling you. We aim to understand you and your business so that you do what you do best unhindered by your IT.

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