Adversaries may abuse ESXi administration services to execute commands on guest machines hosted within an ESXi virtual environment. Persistent background services on ESXi-hosted VMs, such as the VMware Tools Daemon Service, allow for remote management from the ESXi server. The tools daemon service runs as vmtoolsd.exe on Windows guest operating systems, vmware-tools-daemon on macOS, and vmtoolsd on Linux.(Citation: Broadcom VMware Tools Services)
Adversaries may leverage a variety of tools to execute commands on ESXi-hosted VMs – for example, by using the vSphere Web Services SDK to programmatically execute commands and scripts via APIs such as StartProgramInGuest, ListProcessesInGuest, ListFileInGuest, and InitiateFileTransferFromGuest.(Citation: Google Cloud Threat Intelligence VMWare ESXi Zero-Day 2023)(Citation: Broadcom Running Guest OS Operations) This may enable follow-on behaviors on the guest VMs, such as File and Directory Discovery, Data from Local System, or OS Credential Dumping.
Detection Strategy for ESXi Administration Command
User Account Management: User Account Management involves implementing and enforcing policies for the lifecycle of user accounts, including creation, modification, and deactivation. Proper account management reduces the attack surface by limiting unauthorized access, managing account privileges, and ensuring accounts are used according to organizational policies. This mitigation can be implemented through the following measures:
Enforcing the Principle of Least Privilege
Implementing Strong Password Policies
Managing Dormant and Orphaned Accounts
Account Lockout Policies
Multi-Factor Authentication (MFA) for High-Risk Accounts
Restricting Interactive Logins
Tools for Implementation
Built-in Tools:
Identity and Access Management (IAM) Tools:
Privileged Account Management (PAM):
No cross-framework mappings available