In order to tackle the threat of malware attacks, you need antivirus software on all endpoints, a spam filter to block the delivery of malware via email, and DNS protection. One of the measures that can be implemented to block web-based malware delivery is a DNS filter. A DNS filter adds an extra layer of protection to your cybersecurity defenses and prevents employees from visiting malicious websites that host malware or are used to “phish” for sensitive information, such as email credentials.
A DNS filter is a form of content control that uses the Domain Name System (DNS). When an employee or guess user attempts to visit a website, by clicking a link in an email or the web or entering a URL into the browser, a lookup must be performed to translate the URL into an IP address. The DNS lookup ascertains the unique IP address to find the website where the content is located. The DNS filter will check the IP address and, if deemed to be safe, will allow the content to be displayed. This is a very quick process that takes a fraction of a second so there is no noticeable delay in the page load speed. If the IP address or the URL is determined to be malicious, the attempt to access that resource will be blocked.
Cybercriminals sometimes target DNS servers in an attempt to send Internet users to their malicious websites – termed DNS hijacking. Along with this, they may try to hijack control of the web portal by conducting DNS response traffic in Denial of Service campaigns.
Attacks such as these show why businesses need to use DNS malware protection services in order to keep the network safe. Most cybersecurity specialists recommend the addition of DNS security extensions that use digital signature key pairs to authenticate DNS queries and make sure that they are genuine. DNS over TLS encrypts plain text queries to prevent them from being captured and amended in some way or another. DNS over HTTPS is similar to DNS over TLS as encryption is used and replies are hidden internally in other HTTPS traffic. A SIEM system and to share DNS data into the SIEM for additional monitoring and reviewing.
These activities are completed at the point that the DNS lookup is requested for a particular website. The DNS does not spot the difference between genuine websites and malicious spam-laden web pages. However, as all websites have an IP address, and the DNS will share those addresses without question, DNS malware protection can review those IP addresses against blacklists of websites that have been linked with cyberattacks or other nefarious activities to ascertain if they are safe. If an IP address is malicious and blacklisted the request to load it or view it will be denied. A locally-hosted webpage will be served to inform the web user of this.
Why You Should Use DNS Protection Measures
- Filtering takes place before content is displayed on a browser so there is no effect on internet speed.
- Software installations are not necessary.
- Quick and easy configuration process which involves pointing your DNS to the service provider’s DNS servers. The DNS servers used by vendors should be faster than those provided by your ISP.
In addition to protecting your DNS processes, DNS protection measures will prevent attacks from known phishing websites and administrators can place restrictions on the categories of website that employees can access, and by so doing, improve productivity by curbing cyberslacking.
How do DNS filters work?
DNS filtering service providers use a variety of methods for detecting malicious websites. Threat intelligence feeds update blacklists of known malicious URLs, the solutions accurately categorize web pages and websites allowing category-based filtering, restrictions can be placed on URLs containing certain keywords, and the content can be read and scored, with the web page blocked if a certain keyword density threshold is reached.
Why is DNS filtering important?
If you do not have a DNS filter or another type of web filter installed, you must rely on your employees not to violate your Internet usage policies. While most employees will abide by the rules, it only takes one individual to violate the policy to inadvertently download malware. A DNS filter also augments phishing defenses by providing time-of-click protection against malicious links in emails.
Can a DNS filter be bypassed?
Yes. It is not possible to prevent determined individuals from bypassing a DNS filter, but it is possible to reduce that risk to a low and acceptable level by locking down the DNS settings and configuring the DNS filter to prevent the use of anonymizer services.
What are the advantages of a DNS filter over other types of web filters?
Most web filters slow down page load speeds; however, because the DNS filter filters the Internet without downloading content, there is no latency. DNS filters require no additional hardware or software installations, and it is easy to extend coverage to apply and enforce policies for remote workers using corporate-owned mobile devices.
How much does a DNS filter cost?
A DNS-based web filter is a relatively low-cost cybersecurity solution. The cost can vary considerably from provider to provider, with a starting price of around $1.20 per user, per month. The cost can be recovered in terms of the cyberattacks the solution prevents and from the gains in productivity that can be achieved by applying content control policies.