Thermal Zone Temperature

Created the Saturday 26 September 2020. Updated 3 years ago.

The temperature sensor is used to know the current temperature of a machine. In a non-virtualized environment, the function returns valid support and output like: "25.05 C: 77.09 F: 298.2K". But for a fully virtualized environment, the return is "MSAcpi_ThermalZoneTemperature not supported" because this feature is not supported on virtualized processors.

Interestingly, this method is not valid. Not all Windows machines will support this method due to incompatibility with thermal zone sensors. It is a BIOS function. Sometimes the BIOS manufacturer provides dlls that can be referenced to call the required function and return the details.

Many malware authors use it to detect virtual machines, but it frequently fails due to lack of vendor support.

Technique Identifier

U1302

Technique Tags

thermal temperature

Code Snippets

Description

If the return is "MSAcpi_ThermalZoneTemperature not supported, it means you are in a virtualized environment. Reference : https://gist.github.com/teixeira0xfffff/36293713c254c69a7ba2353e8d64afce#file-msacpi_thermalzonetemperature-ps1

function Get-AntiVMwithTemperature {
    $t = Get-WmiObject MSAcpi_ThermalZoneTemperature -Namespace "root/wmi"
    $valorTempKelvin = $t.CurrentTemperature / 10
    $valorTempCelsius = $valorTempKelvin - 273.15
    $valorTempFahrenheit = (9/5) * $valorTempCelsius + 32
    return $valorTempCelsius.ToString() + " C : " + $valorTempFahrenheit.ToString() + " F : " + $valorTempKelvin + "K"  
}

Additional Resources

External Links

The resources provided below are associated links that will give you even more detailed information and research on current evasion technique. It is important to note that, while these resources may be helpful, it is important to exercise caution when following external links. As always, be careful when clicking on links from unknown sources, as they may lead to malicious content.