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

Static analysis result for SHA-256 028efcd673687e3d…

MALICIOUS

Office (OOXML) / .DOCX

684.9 KB Created: 2025-07-01 10:39:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: 83e4e3ceb04db05bf94ab76c90308160 SHA-1: 8f9b6740cba84c7da4e25667ff72add522f6af4a SHA-256: 028efcd673687e3d0a1e395a7f3fb8b43f021ec4743577c7eb967369a5225b0e
522 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is a malicious OOXML document that leverages an embedded RTF object via altChunk. This RTF object exploits CVE-2017-11882 (Equation Editor vulnerability) and CVE-2017-8759 (MSXML SAX OLE activation) to facilitate the execution of an embedded executable. The presence of RTF_MZ_HEX and OOXML_ALTCHUNK_RTF_AUTOUPDATE_PE heuristics confirms the embedding and auto-update of a PE executable.

Heuristics 12

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    (in altChunk RTF word/Toddler.rtf) Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    (in altChunk RTF word/Toddler.rtf) RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    (in altChunk RTF word/Toddler.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.
  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    (in altChunk RTF word/Toddler.rtf) RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • PE header (with DOS stub) in hex data critical RTF_MZ_HEX
    (in altChunk RTF word/Toddler.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/Toddler.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/Toddler.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/Toddler.rtf) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/Toddler.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://www.pdf-tools.com\
    • http://ocsp.entrust.net00
    • http://ocsp.entrust.net05
    • 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
    • http://www.adobe.com/go/security-and-compliance
    • https://acrobat.adobe.com/us/en/
    • http://www.pdf-tools.com
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#
    • http://ns.adobe.com/pdf/1.3/
    • http://crl.entrust.net/g2ca.crl0
    • http://www.entrust.net/rpa0
    • http://aia.entrust.net/ovcs1-chain256.cer01
    • http://crl.entrust.net/ovcs1.crl0J
    • https://www.globalsign.com/repository/0
    • http://ocsp.globalsign.com/ca/gstsacasha384g40C
    • http://secure.globalsign.com/cacert/gstsacasha384g4.crt0
    • http://crl.globalsign.com/ca/gstsacasha384g4.crl0
    • http://ocsp2.globalsign.com/rootr606
    • http://crl.globalsign.com/root-r6.crl0G

Extracted artifacts 11

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0007660e.bin
4405ec63b8cee2ddc242a74fb5ccb136a040e576fd87badb3b5b6c2067ffa5cf
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