September 10, 2019 By David Bisson 2 min read

The RIG exploit kit is distributing a new variant of the Purple Fox downloader malware family that’s capable of abusing PowerShell.

Trend Micro observed that the infection chain for this new Purple Fox variant began when a user visited a malicious site hosting the RIG exploit kit. At that point, the malicious software package used one of three methods to redirect users to a malicious PowerShell command:

  • A Flash (.swf) file that exploited CVE-2018-15982;
  • Two .htm files that exploited CVE-2014-6332 and CVE-2018-8174; or
  • An .hta file.

The PowerShell script, which masqueraded as an image file, then abused the API of msi.dll to execute the main component for Purple Fox.

As 360 Total Security noted, Purple Fox is a downloader Trojan that has affected tens of thousands of users leading up to its initial detection. The newer variant spotted by Trend Micro retained a rootkit component that abused publicly available code. However, the sample differed in that it used PowerShell, thereby enabling fileless attacks in its efforts to deliver cryptomining threats and other malware.

Malware Authors’ Growing Preference for PowerShell

Threat actors have shown a penchant for abusing PowerShell in their attack campaigns this year. Back in late August, Trend Micro spotted a variant of the Asruex backdoor that infected a system via a shortcut file that contained a PowerShell download script. Just a few days later, SecureWorks analyzed a toolkit employed by the LYCEUM threat group in a new Middle East campaign. This assortment of malicious utilities included a PowerShell-based keylogger and a PowerShell script for collecting account information from an infected system.

How to Defend Against RIG Exploit Kit Attacks

Security professionals can help their organizations defend against attacks initiated by the RIG exploit kit by investing in a comprehensive vulnerability management solution that integrates with other security solutions, including security information and event management (SIEM), patch management systems and network modeling tools. Additionally, companies should make sure they monitor for attacks abusing PowerShell by actively searching for malicious PowerShell commands and turning on transcription logs.

More from

X-Force Threat Intelligence Index 2024 reveals stolen credentials as top risk, with AI attacks on the horizon

4 min read - Every year, IBM X-Force analysts assess the data collected across all our security disciplines to create the IBM X-Force Threat Intelligence Index, our annual report that plots changes in the cyber threat landscape to reveal trends and help clients proactively put security measures in place. Among the many noteworthy findings in the 2024 edition of the X-Force report, three major trends stand out that we’re advising security professionals and CISOs to observe: A sharp increase in abuse of valid accounts…

How I got started: Cyber AI/ML engineer

3 min read - As generative AI goes mainstream, it highlights the increasing demand for AI cybersecurity professionals like Maria Pospelova. Pospelova is currently a senior data scientist, and data science team lead at OpenText Cybersecurity. She also worked at Interest, an AI cybersecurity company acquired by MicroFocus and then by OpenText. She continues as part of that team today.Did you go to college? What did you go to school for?Pospelova: I graduated with a bachelor’s degree in computer science and a master’s degree…

Europe’s Cyber Resilience Act: Redefining open source

3 min read - Amid an increasingly complex threat landscape, we find ourselves at a crossroads where law, technology and community converge. As such, cyber resilience is more crucial than ever. At its heart, cyber resilience means maintaining a robust security posture despite adverse cyber events and being able to anticipate, withstand, recover from and adapt to such incidents. While new data privacy and protection regulations like GDPR, HIPAA and CCPA are being introduced more frequently than ever, did you know that there is new…

Topic updates

Get email updates and stay ahead of the latest threats to the security landscape, thought leadership and research.
Subscribe today