Ransomware gangs proceed to utilise a built-in SSH service to facilitate lateral movement and ransomware delivery without being detected.
VMware ESXi hypervisors are being subjected to ransomware intrusions involving the exploitation of SSH tunneling for persistence.
According to research from Sygnia, after infiltrating ESXi instances by leveraging known vulnerabilities or stolen admin credentials, ransomware gangs proceed to utilise a built-in SSH service to facilitate lateral movement and ransomware delivery without being detected, reports BleepingComputer.
“Since ESXi appliances are resilient and rarely shutdown unexpectedly, this tunneLling serves as a semi-persistent backdoor within the network," said Sygnia.
Such findings have prompted researchers to recommend monitoring of four log files for tracking ESXi Shell command execution, conducting admin and user authentication logs, obtaining attempted logins and authentication events, and keeping security event and system logs.
Admins have also been urged to view the hostd.log and vodb.log to identify possible SSH access persistence.
Written by
Dan Raywood is a B2B journalist with 25 years of experience, including covering cybersecurity for the past 17 years. He has extensively covered topics from Advanced Persistent Threats and nation-state hackers to major data breaches and regulatory changes.
He has spoken at events including 44CON, Infosecurity Europe, RANT Forum, BSides Scotland, Steelcon and the National Cyber Security Show, and served as editor of SC Media UK, Infosecurity Magazine and IT Security Guru. He was also an analyst with 451 Research and a product marketing lead at Tenable.
