admin.malware.detector.vbs

' Minimal Malware Detection Script
' Use this when there is an urgent need to look on the C:\ drive
' for new malware programs reported by your agencies.
' It loops through the filename and hash list, searching drive C:\
' on a Windows computer and reports a file with the same MD5 hash.
'
' How to use:
' Poplate the NameAndHash array with multiple comma separated lines
' containing the file name and md5 signature hash.
' Run the file from an admin account with a double click and wait 
' for warnings. The run.malware.detection.as.admin can be used if
' your current login does not have admin priviledge.
' Administrators can include this in a startup or shutdown script,
' running as admin to silently check for threats.
' 
' Command Terminal
' Empty the NameAndHash array then use the command prompt window for
' a single file search, using cscript. You could leave array 
' populated too and the manual entry will be appended to the list.
' Ex:
'    cscript malware.detection.vbs "filename.ext" "MD5HASHSTRING"
'
' Progress reports
' If you have a long list of files, and want to know how it is 
' going, change the "reportSearchProgress" variable to true. It
' will show a dialog box for each file as the search begins.


Dim reportSearchProgress
' Use true if you want notices of progress and problems.
' Use false if you only want a notice when a problem is found.
reportSearchProgress=false

Dim NameAndHash 
' Add the malware filename and MD5 hash list here as comma separated strings.
' At least you need the name,hash fields. Please mind the format!
'   * No extra quotes 
'   * ", _ at the end of multiple entries
'   * only " _ at the end of the last entry
'
' The list below includes Filename, MD5, Bytes, Description

NameAndHash=Array( _
	"malwaremd5.exe,    8D443F2E93A3F0B67F442E4F1D5A4D6D ,48000, Used to calculate md5 hashes",  _
	"badcat.exe,   1854f8385472cf2bo8596988515322ca,78848,fake entry for testing"  _
)

'-------- Know where this script is located. ------------------
strPath = Wscript.ScriptFullName
Set objFSOa = CreateObject("Scripting.FileSystemObject")
Set objFilea = objFSOa.GetFile(strPath)
strFolder = objFSOa.GetParentFolderName(objFilea) 

'-------- Declare additional variables ------------------------
Dim fileData, fileNameParts, foundFileHash, dotLocation, strCommand, i, inputArgs
fileNameParts = Array("","")

Dim FSO2
Set FSO2 = CreateObject("Scripting.FileSystemObject")


'------- If there are command line args, add them to the NameAndHash array
If WScript.Arguments.Count = 2 Then	
	Set args = WScript.Arguments 
	fileData = args.Item(0) & "," & args.Item(1)
	ReDim Preserve NameAndHash(Ubound(NameAndHash)+1)
	NameAndHash(Ubound(NameAndHash)) = fileData
End If


'------- If there is no input, quit. --------------------------
if Ubound(NameAndHash) = -1 Then
	if reportSearchProgress = true then
		MsgBox "Malware.Detection.vbs progress" & vbCrLf & _ 
				 "No, input. Will quit. " & vbCrLf & _ 
				 "Please add to the list in the script or a single file on the command line." &_
				 vbCrLf & "Command Line Usage: "& vbCrLf & vbCrLf & _
				 "   cscript " & Wscript.ScriptName & " ""filename.ext"" ""MD5HASHSTRING"""
	end if
	Wscript.Quit
end if


'-------- Command objects will be used in the search ----------
strComputer = "."
Set objWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set oShortNameChanger = CreateObject("Scripting.FileSystemObject")

	
'-------- Needs the malwaremd5 tool to operate -----------------------
sCurPath = oShortNameChanger.GetFile(strFolder & "\malwaremd5.exe").ShortPath

If fileExists(sCurPath) = false Then
	Wscript.Echo "Malware.Detection.vbs needs malwaremd5.exe to operate." & vbCrLf _
		& vbCrLf & "File: " & sCurPath & " does not exist."
	Wscript.Quit
End If               

' It must also be the correct malwaremd5.exe
strCommand = "%comspec% /c " & sCurPath & " -n " & sCurPath 
         
foundFileHash = fShellRun(strCommand)

if StrComp(foundFileHash,"8D443F2E93A3F0B67F442E4F1D5A4D6D",1) <> 0 then
	WScript.Echo "Malware.Detection.vbs Danger Alert" & vbCrLf _
		& vbCrLf & "File: " & sCurPath & vbCrLf & _ 
                 "MD5: " & foundFileHash & vbCrLf & _
                 "Does not match original MD5: 8D443F2E93A3F0B67F442E4F1D5A4D6D" & vbCrLf &_ 
                 "Do not close this window. " &_
                 "Contact your administrator immediately."
	Wscript.Quit
end if

'------- Loop through the list of malware ---------------------
For Each elem In NameAndHash
	fileData=split(elem,",")
	
	'Trim all the elements of white space on the ends.
	i = 0
	For Each value In fileData
   	fileData(i) = Trim(value)
   	i = i + 1
	Next

	dotLocation = InStrRev(fileData(0),".")
	if dotLocation > 0 Then
		fileNameParts=split(fileData(0),".")
	else
		fileNameParts(0) = fileData(0)
		fileNameParts(1) = "%"               '% Use any extension
	end if

	'Let the search function look for the file and compare the hash
	find_file fileNameParts(0), fileNameParts(1), fileData(1)
Next

'------- Alert the end of the search if requested --------------
if reportSearchProgress = true then
	MsgBox "Malware.Detection.vbs progress" & vbCrLf & "Finished minimal malware scan. "
end if

'------- Function to get the md5 has of the files --------------
Function fShellRun(sCommandStringToExecute)
 ' This function will accept a string as a DOS command to execute.
 ' It will then execute the command in a shell, and capture the output into a file.
 ' That file is then read in and its contents are returned as the value the function returns.
  Dim oShellObject, oFileSystemObject, sShellRndTmpFile
  Dim oShellOutputFileToRead, iErr
  Set oShellObject = CreateObject("Wscript.Shell")
  Set oFileSystemObject = CreateObject("Scripting.FileSystemObject")
  sShellRndTmpFile = oShellObject.ExpandEnvironmentStrings("%temp%") & "\" & oFileSystemObject.GetTempName

  strCommandToRun = sCommandStringToExecute & " > " & sShellRndTmpFile 
  'wscript.echo strCommandToRun
  On Error Resume Next 
   oShellObject.Run strCommandToRun, 0, True
   iErr = Err.Number
  On Error GoTo 0
   If iErr <> 0 Then 
    fShellRun = ""
    Exit Function 
   End If 
  'wscript.echo sshellrndtmpfile
  
  fShellRun = oFileSystemObject.OpenTextFile(sShellRndTmpFile,1).ReadLine
  oFileSystemObject.DeleteFile sShellRndTmpFile, True 
End Function

'------ Looks for the file on the HD and pass to hash test --------
Function find_file(filename, extension, hash)

	'------- Alert the progress per file if requested --------------
	if reportSearchProgress = true then
		WScript.Echo  "Malware.Detection.vbs progress" & vbCrLf _
			& vbCrLf & "Seaching for "& filename & "." & extension
	end if

	'Possible bug is that a virus loads up but somehow avoids registering
	'with the WMI search service. (May or may not be an issue.)
   Set colItems = objWMIService.ExecQuery( _
   	"SELECT * FROM CIM_DataFile " & _
   	"WHERE Drive = 'C:' AND FileName='" & filename & "' AND Extension LIKE '" & extension & "'",,48)
   For Each objItem in colItems
   
      shortFileName=oShortNameChanger.GetFile(objItem.Name).ShortPath
      
      strCommand = "%comspec% /c " & sCurPath & " -n " & shortFileName       	 
     	foundFileHash = fShellRun(strCommand)
      if StrComp(foundFileHash,hash,1) = 0 then
	      WScript.Echo "Malware.Detection.vbs Danger Alert" & vbCrLf _
				& vbCrLf & "File: " & objItem.Name & vbCrLf & _ 
                       "w/MD5: "& foundFileHash & vbCrLf & _
                       "appears to be a malicious program. Do not close this window. " &_
                       "Contact your administrator immediately."
      end if 
   Next
End Function

Function FileExists(strFile)
if FSO2.fileExists(strFile) then
FileExists=true
else
FileExists=false
end if
end function


'Credits:
' find_file main idea: http://leereid.wordpress.com/2010/01/19/vbscript-find-a-file-and-delete-it/
' malwaremd5.exe tool: http://www.fourmilab.ch/md5/
' fShellRun: from: http://www.visualbasicscript.com/fShellRun-m42892.aspx
	'Possible bug is that a virus loads up but somehow avoids registering
	'with the WMI search service. (May or may not be an issue.)
' File Exists http://rosettacode.org/wiki/Check_that_file_exists#VBScript
' Use short path names http://www.visualbasicscript.com/Convert-long-path92filename-to-short-DOSstyle-name-m78126.aspx