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

Static analysis result for SHA-256 d3e0384fc1e93267…

MALICIOUS

Office (OOXML) / .DOCX

685.2 KB Created: 2025-07-01 10:39:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: c2d9176b53b5f2ac0045cf238adcaa36 SHA-1: 15097a57bdfea6a3c578e7d6594a8cc6133e1514 SHA-256: d3e0384fc1e932671fcf881ca900b746195910aa4b60b390e86bb8305b542247
340 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1027 Obfuscated Files or Information T1129 Execution through API

The sample is a DOCX file that utilizes an altChunk to import an RTF object. This RTF object contains OLE data and is configured to auto-update, indicating an attempt to execute embedded content. Critical heuristics like RTF_MZ_HEX and OOXML_ALTCHUNK_RTF_AUTOUPDATE_PE confirm the presence of an executable payload within the imported RTF. The primary attack vector appears to be leveraging the RTF import mechanism to deliver and execute a secondary payload.

Heuristics 9

  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    (in altChunk RTF word/OptimizeDeps.rtf) RTF contains Composite Moniker CLSID in OLE object context, but no nearby scriptlet/SCT payload was confirmed. Treat as related moniker attack-surface evidence rather than proof of CVE-2017-8570 exploitation.
  • 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/OptimizeDeps.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/OptimizeDeps.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/OptimizeDeps.rtf) RTF contains ~1591KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    (in altChunk RTF word/OptimizeDeps.rtf) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/OptimizeDeps.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 11

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0007660e.bin
5004e17d1c01ee0f31f85f6f868c568b1484c51649beb3abc80bd5925234d825
rtf-objdata-decoded RTF \objdata at offset 0x7660E 808586 bytes
objdata_01_off0020cb54.bin
0631cd2b16ce0c99cc02cbd612de1caa4c1ee5ccc6538b4e6a86824d0cd5b585
rtf-objdata-decoded RTF \objdata at offset 0x20CB54 584266 bytes
rtf_svb_004232e6.zip
b5055f2e692cf0e2f1098806fd68a037d4617b1f8b85723c3bdf4a674ef2616c
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4232E6 962 bytes
rtf_svb_004369c2.zip
2189c76bac4052b9338e00ad79591b49a4371fd77f7d1138729d7b77b9385cee
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4369C2 964 bytes
rtf_svb_00449fdd.zip
736996e0e91b3d02f2700e44ea6dce0d44d297bd40de262ab960f58086324a2c
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x449FDD 962 bytes
rtf_svb_0045cc4a.zip
6d52320f1a5409986e188da78532683ae2247e64b7e2c5501cb93d2562a2328a
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x45CC4A 963 bytes
rtf_svb_0046f847.zip
046e2679b1b4f388a9ff4b9e3501e311f9f85253011080324b1128d753c0e7db
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x46F847 964 bytes
rtf_svb_00482e27.zip
a0fd331ad7279ca51fc1f32d13bfbebc03752a4fd4a1fb5e8981f67f6b7ec560
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x482E27 960 bytes
rtf_svb_00495a97.zip
6d4ae2928db79fa88646d0fe5675649d29e26663d5a7034888327ca4d5b3c657
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x495A97 964 bytes
rtf_svb_004964ca.zip
3551f998407b65fc3caff9302b335f1d563c63a2c2465012f77754d307218162
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4964CA 963 bytes
rtf_svb_004972a5.zip
1356ef9ff238819061f9bee5ae66c1e490997afa46929b3f1174d90b79894daa
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4972A5 964 bytes