Adversaries may use anti-virtualization techniques to evade detection in virtualized environments. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify potential evasion tactics and uncover hidden malicious activity.
YARA Rule
rule vmdetect
{
meta:
author = "nex"
description = "Possibly employs anti-virtualization techniques"
strings:
// Binary tricks
$vmware = {56 4D 58 68}
$virtualpc = {0F 3F 07 0B}
$ssexy = {66 0F 70 ?? ?? 66 0F DB ?? ?? ?? ?? ?? 66 0F DB ?? ?? ?? ?? ?? 66 0F EF}
$vmcheckdll = {45 C7 00 01}
$redpill = {0F 01 0D 00 00 00 00 C3}
// Random strings
$vmware1 = "VMXh"
$vmware2 = "Ven_VMware_" nocase
$vmware3 = "Prod_VMware_Virtual_" nocase
$vmware4 = "hgfs.sys" nocase
$vmware5 = "mhgfs.sys" nocase
$vmware6 = "prleth.sys" nocase
$vmware7 = "prlfs.sys" nocase
$vmware8 = "prlmouse.sys" nocase
$vmware9 = "prlvideo.sys" nocase
$vmware10 = "prl_pv32.sys" nocase
$vmware11 = "vpc-s3.sys" nocase
$vmware12 = "vmsrvc.sys" nocase
$vmware13 = "vmx86.sys" nocase
$vmware14 = "vmnet.sys" nocase
$vmware15 = "vmicheartbeat" nocase
$vmware16 = "vmicvss" nocase
$vmware17 = "vmicshutdown" nocase
$vmware18 = "vmicexchange" nocase
$vmware19 = "vmdebug" nocase
$vmware20 = "vmmouse" nocase
$vmware21 = "vmtools" nocase
$vmware22 = "VMMEMCTL" nocase
$vmware23 = "vmx86" nocase
$vmware24 = "vmware" nocase
$virtualpc1 = "vpcbus" nocase
$virtualpc2 = "vpc-s3" nocase
$virtualpc3 = "vpcuhub" nocase
$virtualpc4 = "msvmmouf" nocase
$xen1 = "xenevtchn" nocase
$xen2 = "xennet" nocase
$xen3 = "xennet6" nocase
$xen4 = "xensvc" nocase
$xen5 = "xenvdb" nocase
$xen6 = "XenVMM" nocase
$virtualbox1 = "VBoxHook.dll" nocase
$virtualbox2 = "VBoxService" nocase
$virtualbox3 = "VBoxTray" nocase
$virtualbox4 = "VBoxMouse" nocase
$virtualbox5 = "VBoxGuest" nocase
$virtualbox6 = "VBoxSF" nocase
$virtualbox7 = "VBoxGuestAdditions" nocase
$virtualbox8 = "VBOX HARDDISK" nocase
// MAC addresses
$vmware_mac_1a = "00-05-69"
$vmware_mac_1b = "00:05:69"
$vmware_mac_1c = "000569"
$vmware_mac_2a = "00-50-56"
$vmware_mac_2b = "00:50:56"
$vmware_mac_2c = "005056"
$vmware_mac_3a = "00-0C-29" nocase
$vmware_mac_3b = "00:0C:29" nocase
$vmware_mac_3c = "000C29" nocase
$vmware_mac_4a = "00-1C-14" nocase
$vmware_mac_4b = "00:1C:14" nocase
$vmware_mac_4c = "001C14" nocase
$virtualbox_mac_1a = "08-00-27"
$virtualbox_mac_1b = "08:00:27"
$virtualbox_mac_1c = "080027"
condition:
any of them
}This YARA rule can be deployed in the following contexts:
This rule contains 62 string patterns in its detection logic.
Scenario: Virtual Machine Guest Tools are Being Used for System Monitoring
Description: A system administrator is using tools like vmtoolsd (VMware) or vssd (VirtualBox) to monitor system performance or collect logs.
Filter/Exclusion: Check for process names containing vmtoolsd, vssd, or guesttools and exclude processes running under the root or system user.
Scenario: Scheduled System Maintenance Tasks
Description: A scheduled task is running a script that checks for system health, updates, or performs disk cleanup, which may include checking for virtualization features.
Filter/Exclusion: Exclude processes with schtasks.exe or at.exe (Windows) or cron jobs (Linux) that are part of standard maintenance routines.
Scenario: Anti-Virus or Security Software Scanning for Virtualization Features
Description: Security software like Malwarebytes, Kaspersky, or Bitdefender may scan for virtualization features as part of their heuristic analysis.
Filter/Exclusion: Exclude processes associated with known security tools (e.g., mbam.exe, kavservice.exe, bdagent.exe) or those running under the LocalSystem account.
Scenario: Development Environment with Virtual Machines
Description: A developer is using a virtual machine (e.g., Vagrant, Docker, or VirtualBox) for testing or development purposes.
Filter/Exclusion: Exclude processes related to virtualization platforms (e.g., VBoxHeadless, dockerd, vagrant) or those running in a development environment with known VM usage.
Scenario: System Performance Monitoring Tools
Description: Tools like PerfMon (Windows) or sar (