The Neptune Exploit kit is being used to turn computers into cryptocurrency miners, with traffic directed to the exploit kit using a hiking-themed malvertising campaign.

Exploit kit activity has fallen this year, although these web-based attacks still pose a significant threat. Exploit kits are web-based toolkits that probe browsers and plugins for vulnerabilities that can be exploited to download malware. Simply visiting a website hosting an exploit kit is all it takes for malware to be silently downloaded.

Protecting against exploit kit attacks requires browsers, plugins and extensions to be kept 100% up to date. However, even updated browsers can be vulnerable. Exploit kits can also include exploits for zero-day vulnerabilities that have not yet been patched.

Acceptable usage policies can help organizations to prevent exploit kit attacks, although website visitors are often redirected to malicious sites from legitimate websites. One of the main ways this happens is the use of malvetisements. Many high traffic websites include advertising blocks that display third-party adverts. The advertising networks serve adverts which are displayed on member sites, with the site owners earning money from ad impressions and click throughs.

While the advertising networks have measures in place to vet advertisers, oftentimes cybercriminals succeed in submitting malicious adverts. Those adverts are then pushed out and displayed on legitimate websites. Clicking one of those malicious adverts will see the user directed to a webpage hosting the exploit kit.

Exploit kits are used to download Trojans, ransomware and other malicious code, although the Neptune exploit kit is being used to download cryptocurrency miners. Infection will see computers’ processing power used to mine the Monero cryptocurrency. Infection will result in the infected computer’s resources being hogged, slowing down the performance of the machine.

The latest Neptune exploit kit campaign uses hiking club-related adverts to drive traffic to landing pages hosting the Neptune exploit kit, which in turn uses HTML and Flash exploits to download malware. These adverts closely mimic genuine domains. FireEye reports that one such campaign mimics the genuine website highspirittreks[.]com using the domain highspirittreks[.]club. Other campaigns offer a service to convert Youtube videos to MP3 files. The imageryused in the adverts is professional and the malvertising campaigns are likely to fool many web surfers.

The exploits used in the latest campaign are all old, therefore, protecting against attacks simply requires plugins and browsers to be updated. The main exploits take advantage of flaws in Internet Explorer – CVE-2016-0189, CVE-2015-2419, CVE-2014-6332 – and Adobe Flash – CVE-2015-8651, CVE-2015-7645.

Having a computer turned into a cryptocurrency miner may not be the worst attack scenario, although exploit kits can rapidly switch their payload. Other exploit kits are being used to deliver far more damaging malware, which will be downloaded silently without the user’s knowledge. Consequently, organizations should take precautions.

In addition to prompt patching and updating of software, organizations can improve their defences against exploit kits by implementing a web filtering solution such as WebTitan.

WebTitan can be configured to block all known malicious sites where drive-by downloads take place and can prevent malvertisements from directing end users to webpages hosting these malicious toolkits.

To find out more about WebTitan and how it can improve your organization’s security posture, contact the TitanHQ team today.