VMware released a threat report titled Exposing Malware in Linux-based Multi-Cloud Environments and the key findings that detail how cybercriminals are using malware to target Linux-based operating systems include:
- Ransomware is evolving to target Linux host images used to spin workloads in virtualized environments;
- 89 percent of cryptojacking attacks use XMRig-related libraries; and
- More than half of Cobalt Strike users may be cybercriminals, or at least using Cobalt Strike illicitly.
“Cybercriminals are dramatically expanding their scope and adding malware that targets Linux-based operating systems to their attack toolkit in order to maximize their impact with as little effort as possible,” said Giovanni Vigna, senior director of threat intelligence at VMware.
“Rather than infecting an endpoint and then navigating to a higher value target, cybercriminals have discovered that compromising a single server can deliver the massive payoff and access they’re looking for. Attackers view both public and private clouds as high-value targets due to the access they provide to critical infrastructure services and confidential data. Unfortunately, current malware countermeasures are mostly focused on addressing Windows-based threats, leaving many public and private cloud deployments vulnerable to attacks on Linux-based operating systems,” Vigna added.
As malware targeting Linux-based operating systems increases in both volume and complexity amid a rapidly changing threat landscape, organizations must place a greater priority on threat detection. In this report, the VMware Threat Analysis Unit (TAU) analyzed the threats to Linux-based operating systems in multi-cloud environments: ransomware, cryptominers, and remote access tools.
VMware TAU discovered more than 14,000 active Cobalt Strike Team Servers on the Internet between February 2020 and November 2021. The total percentage of cracked and leaked Cobalt Strike customer IDs is 56 percent, meaning that more than half of Cobalt Strike users may be cybercriminals, or at least using Cobalt Strike illicitly. The fact that RATs like Cobalt Strike and Vermilion Strike have become a commodity tool for cybercriminals poses a significant threat to enterprises.
“Since we conducted our analysis, even more ransomware families were observed gravitating to malware targeting Linux-based systems, with the potential for additional attacks that could leverage the Log4j vulnerabilities,” said Brian Baskin, manager of threat research at VMware. “The findings in this report can be used to better understand the nature of this malware and mitigate the growing threat that ransomware, cryptomining, and RATs have on multi-cloud environments. As attacks targeting the cloud continue to evolve, organizations should adopt a Zero Trust approach to embed security throughout their infrastructure and systematically address the threat vectors that make up their attack surface.”