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

Static analysis result for SHA-256 11c046fa1cf8a97c…

MALICIOUS

Office (OOXML) / .DOCX

274.3 KB
MD5: cced9bb9f570043bfb77965ab3df8bf5 SHA-1: 46d8bb1a992cffd02c2c6086db0779e5f85b4159 SHA-256: 11c046fa1cf8a97cdd919506d516e6363f8b35b58d70ee1cefab714060d85b2e
442 Risk Score

Malware Insights

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

The sample is a DOCX file that leverages an altChunk to import an RTF document. This RTF document contains an embedded OLE object exploiting CVE-2017-11882 via the Equation Editor. The exploit is designed to automatically update and execute an embedded PE file, likely serving as a downloader for a second-stage payload.

Heuristics 11

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    (in altChunk RTF word/Barbados.rtf) RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    (in altChunk RTF word/Barbados.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/Barbados.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/Barbados.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/Barbados.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/Barbados.rtf) RTF contains ~1048KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    (in altChunk RTF word/Barbados.rtf) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/Barbados.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://ocsp.verisign.com0
    • http://ocsp.digicert.com0C
    • http://ocsp.digicert.com0A
    • http://ocsp.digicert.com0X
    • 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.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/
    • https://www.verisign.com/rpa
    • http://csc3-2010-crl.verisign.com/CSC3-2010.crl0D
    • https://www.verisign.com/rpa0
    • http://csc3-2010-aia.verisign.com/CSC3-2010.cer0
    • http://cacerts.digicert.com/DigiCertAssuredIDRootCA.crt0E
    • http://crl3.digicert.com/DigiCertAssuredIDRootCA.crl0
    • https://www.verisign.com/cps0*
    • http://logo.verisign.com/vslogo.gif04
    • http://crl.verisign.com/pca3-g5.crl04
    • http://cacerts.digicert.com/DigiCertTrustedRootG4.crt0C
    • http://crl3.digicert.com/DigiCertTrustedRootG4.crl0
    • http://crl3.digicert.com/DigiCertTrustedG4RSA4096SHA256TimeStampingCA.crl0��
    • http://cacerts.digicert.com/DigiCertTrustedG4RSA4096SHA256TimeStampingCA.crt0

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00022ce6.bin
cc6eec71ef60053916e73b0b64b363511009d09380b38d918650d74d210d34a5
rtf-objdata-decoded RTF \objdata at offset 0x22CE6 495698 bytes
objdata_01_off001205bc.bin
56684de9a3a82fd5fe392f331efb0aef7d8f1ca301483bc8e8af8263a6e0e72b
rtf-objdata-decoded RTF \objdata at offset 0x1205BC 534490 bytes
rtf_svb_00002c19.zip
d39b64319316e088a3b732b0bbaad03692be6c735566f33d475288af16e459ea
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x2C19 8890 bytes