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

Static analysis result for SHA-256 c2c47c5d916ee713…

MALICIOUS

Office (OOXML) / .DOCX

187.0 KB Created: 2020-01-30 08:31:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: 3fa4497e25c607201f52d241a8e2db2d SHA-1: 871b5b9a8b12205261fb96f74bf8e201767f6d9e SHA-256: c2c47c5d916ee713b33de4c3c4a3fc670eae8832735c3f032fa84f882813dae4
300 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1203 Exploitation for Client Execution

The sample is a malicious OOXML document that leverages RTF injection via altChunk to import an embedded OLE object. Critical heuristics indicate exploitation of CVE-2017-8759 and CVE-2026-21514, which are known to facilitate arbitrary code execution. The embedded RTF object is likely responsible for downloading and executing a second-stage payload, although the specific mechanism is not fully detailed in the provided heuristics. The SHA256 hash is included as a primary IOC.

Heuristics 8

  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    (in altChunk RTF word/eliev.xml) 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.
  • CVE-2026-21514 — Word/OLE security bypass in RTF high CVE likely CVE_2026_21514
    (in altChunk RTF word/eliev.xml) RTF contains a hidden \svb hex package with DrsE2oDoc and downRevStg drawing compatibility parts. This matches an observed CVE-2026-21514 exploitation shape that manipulates Word's internal document structure and trust decisions.
  • 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/eliev.xml) 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.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    (in altChunk RTF word/eliev.xml) RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    (in altChunk RTF word/eliev.xml) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/eliev.xml) 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://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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000a967c.bin
df2e5c72e67ce4fe0761e545689b962309b1ba1505b9b6cb85e2cb5c47d128d2		 rtf-objdata-decoded RTF \objdata at offset 0xA967C 64066 bytes
objdata_01_off000d3a7d.bin
1beb1c8cc694fc56227f4282483d1189c1500359e13117fad4cb7330870c91d6		 rtf-objdata-decoded RTF \objdata at offset 0xD3A7D 694188 bytes
rtf_svb_00000009.zip
28fc295dafc0bcccd998d6dc34a4e9ae47eb34cb74cb4b892eb6454833467799		 rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x9 116932 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.