VMToolsd Suspicious Child Process
A Sigma rule for process creation on Windows, by bohops, Bhabesh Raj.
high 1 ATT&CK technique 8 programs it names
What it looks for
detection:
filter_main_empty:
CommandLine: ''
Image|endswith: '\cmd.exe'
filter_main_null:
CommandLine: null
Image|endswith: '\cmd.exe'
filter_main_vmwaretools_script:
CommandLine|contains:
- '\VMware\VMware Tools\poweron-vm-default.bat'
- '\VMware\VMware Tools\poweroff-vm-default.bat'
- '\VMware\VMware Tools\resume-vm-default.bat'
- '\VMware\VMware Tools\suspend-vm-default.bat'
Image|endswith: '\cmd.exe'
selection_img:
- Image|endswith:
- '\cmd.exe'
- '\cscript.exe'
- '\mshta.exe'
- '\powershell.exe'
- '\pwsh.exe'
- '\regsvr32.exe'
- '\rundll32.exe'
- '\wscript.exe'
- OriginalFileName:
- 'Cmd.Exe'
- 'cscript.exe'
- 'MSHTA.EXE'
- 'PowerShell.EXE'
- 'pwsh.dll'
- 'REGSVR32.EXE'
- 'RUNDLL32.EXE'
- 'wscript.exe'
selection_parent:
ParentImage|endswith: '\vmtoolsd.exe'
condition: all of selection* and not 1 of filter_main_*
The rule’s detection, its selections and fields in order of name. The whole rule, with its references and false positives, is on SigmaHQ, by bohops, Bhabesh Raj, under the Detection Rule License 1.1. CmdID evaluates it on a command line alone: a test on what a command line cannot show, such as the parent process or the user, is not met.
None of the everyday examples and documented commands on CmdID’s program pages trips it. To see whether a command line does, paste it into CmdID.
Programs and files it names
ATT&CK
T1059Command and Scripting Interpreter