The Spelevo exploit kit is being used to deliver Maze ransomware to unsuspecting internet users via a vulnerability in Adobe Flash Player.
The Spelevo exploit kit has been used to deliver a variety of malicious payloads since it was first detected in early 2019. Initially it was used to silently download the GootKit Trojan, and latterly the Dridex and IceD banking Trojans. Now the threat actors behind Maze ransomware have joined forces with the EK developers to deliver their malicious payload.
Spelevo has previously been loaded onto a compromised business-to-business contact website to target business users, although the latest campaign uses ad network traffic to send users to a fake cryptocurrency website, where they are then redirected to a web page hosting the exploit kit.
The Flash Vulnerability – CVE-2018-15982 – is then exploited in the browser to silently download and execute the ransomware payload. If that download occurs, the user’s files will be encrypted. There is currently no free decryptor for Maze ransomware. Recovery will depend on restoring files from backups – provided they too have not also been encrypted – or the user will face permanent file loss if they do not pay the ransom demand. The ransom doubles if payment is not made within a week.
Exploit kits used to be one of the main ways that malware was distributed, although they fell out of favor with cybercriminals who found alternate, more profitable ways to earn money. The threat never disappeared but exploit kit activity dropped to a tiny fraction of the level seen a few years ago when Angler exploit kit activity was at its peak. However, over the past year or so, exploit kit activity has been increasing. Today, there are several active exploit kits that are being used to deliver a variety of malware and ransomware payloads.
Exploit kits will only work if they have been loaded with an exploit for a vulnerability that has not been patched on a user’s device. Prompt patching will ensure that even if a user lands on a web page hosting an exploit kit, no malware download will take place. However, many businesses are slow to apply patches and it can be several months before vulnerabilities are corrected.
One of the best defenses against exploit kits is a DNS filter. A DNS filter is a control mechanism used to prevent users from visiting malicious websites. With a DNS filter in place, websites known to host malware or malicious code are blocked at the DNS lookup stage, before any content is downloaded. If a user attempts to visit a known malicious web page, they will be directed to a block screen instead.
Web filters can also be used to prevent ‘risky’ file types from being downloaded, such as .exe, .scr, or .js files. In addition to blocking malware downloads, a DNS filter can be used by businesses to enforce their acceptable internet usage policies and prevent employees from accessing productivity-draining websites and adult content.
A web filter is an important part of layered defenses against malware and other internet-based attacks such as phishing. TitanHQ’s DNS filter, WebTitan, is used by thousands of businesses and managed service providers to protect against web-based threats. WebTitan blocks more than 60,000 new malware sites every day and provides businesses and MSPs with real-time protection against the full range of web-based threats.
WebTitan can be deployed in minutes, is updated automatically, highly scalable, and costs as little as 90 cents per user per month. The productivity gains alone from using the solution mean it more than pays for itself, let alone the savings from preventing phishing attacks and costly malware downloads and data breaches.
To find out more about DNS filtering and why it is now considered an essential part of layered security defenses, give the TitanHQ team a call. Our support staff will be happy to answer your questions, book a product demonstration, and help you get set up for a free trial.