cybersecurity

Running suspicious software in a virtual machine seems like a basic precaution to figure out whether said software contains naughty code. Unfortunately it’s generally rather easy to detect whether or not one’s software runs inside a VM, with [bRootForce] going through a list of ways that a VirtualBox VM can be detected from inside the guest OS. While there are a range of obvious naming issues, such as the occurrence of the word ‘VirtualBox’ everywhere, there many more subtle ways too.

Demonstrated is the PoC ‘malware’ application called Al-Khaser, which can be used to verify one’s anti-malware systems, such as when trying to unleash a debugger on a piece of malware, run it inside a VM, along with many more uses. Among its anti-virtualization features are specific registry key names and values, file system artefacts, directory names, MAC addresses, virtual devices, etc.

In order to squeeze by those checks, [bRootForce] created the vbox_stealth shell script for Bash-blessed systems in order to use the VirtualBox Manager for the renaming of hardware identifier, along with the VBoxCloak project’s PowerShell script that’s used inside a Windows VirtualBox guest instance to rename registry keys, kill VirtualBox-specific processes, and delete VirtualBox-specific files.