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

Static analysis result for SHA-256 30bc286d51ebf70b…

MALICIOUS

Office (OOXML) / .DOCX

314.9 KB
MD5: 8032a47e4d3563b4f47d84fc63fd05dc SHA-1: 403a574785a0cd7bfc129b31cfa41aa588836623 SHA-256: 30bc286d51ebf70b480295ea9fd6f4df661732b97cc1ac87fbd060cc4132610f
300 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking T1137.001 DLL Search Order Hijacking

The OOXML document utilizes an altChunk to import an RTF file named 'Nepal.rtf'. This RTF file contains OLE objects that are automatically updated and executed, indicated by RTF_OBJUPDATE and RTF_MZ_HEX heuristics. This mechanism is commonly used to embed and execute malicious executables, suggesting the document's primary purpose is to act as a dropper for a second-stage payload.

Heuristics 8

  • altChunk imports embedded RTF (RTF injection) critical OOXML_ALTCHUNK_RTF
    Document inlines an embedded RTF via an aFChunk relationship and a <w:altChunk> body element. This is the canonical RTF-injection wrapper used to smuggle RTF exploits (Equation Editor / URL Moniker / objdata) past DOCX-only scanners. Word opens the wrapper and executes the RTF inline. Recursing into the RTF for the exact exploit primitive.
  • PE header (with DOS stub) in hex data critical RTF_MZ_HEX
    (in altChunk RTF word/Nepal.rtf) Hex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
  • altChunk RTF auto-updates embedded executable object critical OOXML_ALTCHUNK_RTF_AUTOUPDATE_PE
    OOXML document imports an embedded RTF through altChunk; the RTF contains OLE object data, forces object update, and carries a hex-encoded PE payload. This is a stronger compound exploit-loader shape than a generic altChunk RTF wrapper, but it is not tied to a single CVE unless the nested RTF object primitive also matches one.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    (in altChunk RTF word/Nepal.rtf) RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    (in altChunk RTF word/Nepal.rtf) RTF contains ~2071KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    (in altChunk RTF word/Nepal.rtf) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/Nepal.rtf) RTF contains \objemb — embedded OLE object
  • 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://opendope.org/xpaths
    • http://opendope.org/conditions
    • http://opendope.org/questions
    • http://opendope.org/components
    • http://opendope.org/SmartArt/DataHierarchy
    • http://schemas.openxmlformats.org/wordprocessingml/2006/main
    • http://schemas.openxmlformats.org/officeDocument/2006/math
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing
    • http://schemas.openxmlformats.org/drawingml/2006/main
    • http://schemas.openxmlformats.org/schemaLibrary/2006/main
    • http://schemas.openxmlformats.org/drawingml/2006/chart
    • http://schemas.openxmlformats.org/drawingml/2006/chartDrawing
    • http://schemas.openxmlformats.org/drawingml/2006/diagram
    • http://schemas.openxmlformats.org/drawingml/2006/picture
    • http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing
    • http://schemas.microsoft.com/office/drawing/2008/diagram
    • http://schemas.openxmlformats.org/officeDocument/2006/bibliography
    • http://schemas.openxmlformats.org/drawingml/2006/compatibility
    • http://schemas.openxmlformats.org/drawingml/2006/lockedCanvas

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000800a1.bin
6996de20483f2fa4b61ce731fde1bf40eb3219708a8932dc68dd9b39f62e5a68
rtf-objdata-decoded RTF \objdata at offset 0x800A1 788065 bytes
objdata_01_off0020bdb6.bin
4a82d047d6ef350abf1adf2f1f3cef562ce575c77ef4edb29c91f5ec96920c07
rtf-objdata-decoded RTF \objdata at offset 0x20BDB6 198784 bytes