mshta terminates itself immediately. Maybe it’s too late to achieve parent process id by using WMI service.
So, I’d use something like this to eliminate concurrent script processes.
- Generate random things.
- Determine an application which could be installed on each system, never terminates by itself (e.g. command prompt with /k parameter).
- Start the application in hidden mode with generated random argument (WshShell.Run).
- Wait a few milliseconds
- Query the running processes by using command line argument value.
- Get the ParentProcessId property.
Function CurrProcessId
Dim oShell, sCmd, oWMI, oChldPrcs, oCols, lOut
lOut = 0
Set oShell = CreateObject("WScript.Shell")
Set oWMI = GetObject(_
"winmgmts:{impersonationLevel=impersonate}!\\.\root\cimv2")
sCmd = "/K " & Left(CreateObject("Scriptlet.TypeLib").Guid, 38)
oShell.Run "%comspec% " & sCmd, 0
WScript.Sleep 100 'For healthier skin, get some sleep
Set oChldPrcs = oWMI.ExecQuery(_
"Select * From Win32_Process Where CommandLine Like '%" & sCmd & "'",,32)
For Each oCols In oChldPrcs
lOut = oCols.ParentProcessId 'get parent
oCols.Terminate 'process terminated
Exit For
Next
CurrProcessId = lOut
End Function
Dim ProcessId
ProcessId = CurrProcessId 'will remain valid indefinitely
WScript.Echo ProcessId