Phishing attacks are increasing and malware is a growing threat. A DNS filter adds an important level of protection to block these attacks. In this post we explain why.
The Growing Threat from Malware and Phishing Attacks
There are various methods used to deliver malware, but email remains one of the most common methods of distributing malware, either through malicious attachments or hyperlinks in emails that direct users to websites where malware is downloaded. The latter is a popular method of malware delivery as there is an increased chance that the hyperlink will not be detected as malicious by an email security solution. Various tactics are used to mask these URLs from email security solutions, such as adding the hyperlink to an attached file such as a PDF.
The Emotet Trojan is one of the most prevalent threats and also one of the most dangerous. Emotet is primarily spread via email through a combination of attachments and malicious URLs. The Trojan is an information stealer capable of spreading across networks to infect other vulnerable devices. Removing the malware is problematic, as there are usually multiple devices infected. As soon as the malware is removed from one device, others on the network re-infect the cleaned machine. Emotet is also a malware downloader. Once all valuable information has been obtained post-infection, other malware variants such as the TrickBot Trojan and RYUK ransomware are downloaded. All devices infected with Emotet are added to the botnet. An analysis by the SpamHaus project revealed around 6,000 malicious URLs are emitted from infected devices, which act as compromise vectors.
An advanced spam filter will ensure that the majority of malicious emails are blocked, but it is important not to totally rely on a spam filter alone to block email-based malware and phishing attacks. The key to a strong defense is to implement layered defenses. With overlapping layers of security, if one layer fails to block a threat, another is in place to provide protection. One of the most important additional protections against phishing attacks and email-based malware is a web filter.
Why a Web Filter is so Important
Phishing attacks have an email and web-based component. The email contains the lure and a hyperlink is included that directs the recipient to a webpage hosting a phishing kit. When the user visits the website credentials and other sensitive information is harvested. A spam filter will block most of these phishing emails and a web filter provides protection against emails that are not blocked, as well as protecting against accidental navigation to malicious websites through malvertising or general web browsing.
A web filter is a form of content control that prevents network users from visiting known malicious websites. When a network user attempts to visit a malicious website, rather than connecting to the site, they are directed to a block page. That block page informs the user that they have attempted to visit a prohibited website which, in this case is a phishing page or website hosting malware. It could equally be a website that violates an organization’s internet usage policies. A web filter therefore serves as an additional, and important, layer of security to block phishing attacks and malware and ransomware downloads.
Web Filtering Options
There are different web filtering options available. Appliance-based web filters were once the go-to solution, but cloud-based filtering is now much more common, more cost effective for most organizations, and easier to implement and maintain.
Appliance-based solutions are not scalable. Once capacity has been reached, another appliance must be purchased. Software-based web filters, which are usually deployed as a virtual appliance on existing hardware, are a good choice but the most popular web filtering solutions are cloud-based. With cloud-based web filters, all filtering takes place in the cloud on the service provider’s hardware. Cloud-based filters are highly scalable. If capacity is increased, additional licenses just need to be purchased which takes seconds.
DNS Filtering is the Most Flexible Web Filtering Choice
The most popular, flexible, and scalable solution is a DNS filter. When a user makes a request to visit a website, such as by clicking a hyperlink or navigating to a website through their browser, a set of procedures must be followed to display the content.
One of the first steps is to send a query to the DNS server. The DNS server matches an easy to remember domain name – google.com for instance – with an IP address that allows the site to be found. A DNS filter works at this stage of the process and will block attempts to visit prohibited websites or malicious sites before any content is downloaded. Modern DNS filters do not just block content at the domain level. They also block content at the URL and page level. This means that a page on Medium.com could be blocked, while other content on the site is allowed. This means filtering controls are very granular and there is less potential for overblocking of web content.
WebTitan – A DNS Filter for SMBs and MSPs Serving the SMB Market
TitanHQ’s DNS filtering solution – WebTitan – has been developed for use by SMBs, MSPs providing security services to SMBs, and ISPs with millions of users. WebTitan includes market-leading classification of web content and malicious URL detection, and the solution is updated in real-time with more than 60,000 malicious URLs added to the filter every day. The solution includes advanced analytics and threat intelligence feeds and covers more than 99.9% of the active web. The solution is also easy to integrate into your own systems through TitanHQ’s API, and the solution can be purchased, set up, and be providing protection in just a few minutes.
For more information on WebTitan, to sign up for a free trial, or to book a product demonstration, give the TitanHQ team a call today.