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

Static analysis result for SHA-256 7b65cf782881267e…

MALICIOUS

Office (OOXML) / .DOCX

681.8 KB Created: 2025-10-22 14:54:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: b22b00b9c7a4e3211ecf9bd1c27da8e0 SHA-1: d85222e41e3f2ca2846cc2df56bb22b6984b03c4 SHA-256: 7b65cf782881267e48afe3a4997909b922396e3896f8379e13ad145eb6a61d72
542 Risk Score

Malware Insights

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

The sample is a malicious OOXML document that leverages altChunk to import an RTF object. This RTF object contains exploits for CVE-2017-11882 and CVE-2017-8759, which are known to execute embedded OLE objects. The presence of RTF_MZ_HEX and PE header data within the RTF object strongly indicates the embedded OLE object is an executable payload. The external relationship points to a template file, suggesting this document was likely delivered via spearphishing.

Heuristics 13

  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    (in altChunk RTF word/Visibi.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.
  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    (in altChunk RTF word/Visibi.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/Visibi.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/Visibi.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/Visibi.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/Visibi.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/Visibi.rtf) RTF contains ~1797KB of hex-encoded data inside \objdata sections — may hide a payload
  • External relationship high OOXML_EXTERNAL_REL
    External target in word/_rels/settings.xml.rels: file:///C:\Users\John\AppData\Roaming\Microsoft\Templates\Student report with photo.dotx
  • OLE object data medium RTF_OBJDATA
    (in altChunk RTF word/Visibi.rtf) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/Visibi.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://www.pdf-tools.com\
    • http://ocsp.entrust.net00
    • http://ocsp.entrust.net05
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas
    • http://schemas.microsoft.com/office/drawing/2014/chartex
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/officeDocument/2006/math
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawing
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing
    • http://schemas.openxmlformats.org/wordprocessingml/2006/main
    • http://schemas.microsoft.com/office/word/2010/wordml
    • http://schemas.microsoft.com/office/word/2012/wordml
    • http://schemas.microsoft.com/office/word/2015/wordml/symex
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroup
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInk
    • http://schemas.microsoft.com/office/word/2006/wordml
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShape
    • 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 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000af6e7.bin
60a95401f0cabf92473fc20ec9e5814a6b85bcbd722d9d39c8efe185b1db8045
rtf-objdata-decoded RTF \objdata at offset 0xAF6E7 794762 bytes
objdata_01_off0023ef57.bin
24ee741dd41bc27803d80f81b66eba686fe8f5d17bd847727dc5d94834bd3188
rtf-objdata-decoded RTF \objdata at offset 0x23EF57 584826 bytes
rtf_svb_00000009.zip
008e94dd68af4600885d76f18087f8d35d4040e2308364d905db626e7fc4307c
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x9 116840 bytes
rtf_svb_00443e53.zip
a463062fa4912b21a38e780ed3e90eaa5c5b691e2da561ae5b20c5c201fb80f6
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x443E53 963 bytes
rtf_svb_004452fe.zip
1db5fafdb39a4e25cd63c0d17ee124d74679ca9fa60ca30d59caa7391aab0069
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4452FE 964 bytes
rtf_svb_0047d7cd.zip
53fff4488b7672eecc77c890505a45d3ecfc7a7654d7482c0a7d5b59e04ea302
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x47D7CD 964 bytes