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

Static analysis result for SHA-256 854257f1be039d9d…

MALICIOUS

Office (OOXML) / .DOCX

233.4 KB Created: 2020-01-30 08:31:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2026-06-11
MD5: 9d155976ffa72b31e80bafe1cde0497d SHA-1: cd9c9b4672ab370c914f5986b6e49d171999180f SHA-256: 854257f1be039d9dd40464c206bd8c115fdd520eb9c2af7f7747633e5face2c6
302 Risk Score

Malware Insights

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

The sample is a DOCX file that leverages the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This vulnerability allows for arbitrary code execution when the embedded OLE object is activated. The presence of RTF injection and OLE object data strongly indicates exploitation of this known vulnerability.

Heuristics 8

  • Split hex Equation Editor ProgID + OLE object critical CVE likely RTF_EQUATION_EDITOR
    (in altChunk RTF word/uton.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.
  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    (in altChunk RTF word/uton.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.
  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    (in altChunk RTF word/uton.xml) 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.
  • 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.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    (in altChunk RTF word/uton.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/uton.xml) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/uton.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 In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)

Extracted artifacts 10

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000a967c.bin rtf-objdata-decoded RTF \objdata at offset 0xA967C 194747 bytes
SHA-256: 46c95921dffbc1a653176b7311d5091cf49e03baf7769c8fcc847d4d89f580af
objdata_01_off0011376f.bin rtf-objdata-decoded RTF \objdata at offset 0x11376F 693522 bytes
SHA-256: 21b35263b4bf7fa7c864b01428696c8b3cf264dc87cdcf3aa12494d206da65a7
rtf_svb_0038c721.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x38C721 967 bytes
SHA-256: b461da4154fae7bb965448788af03a71a043eb99efb0e1486728dba51d84fefb
rtf_svb_0038d6c5.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x38D6C5 964 bytes
SHA-256: fd1e102bcb6b99544d5f496230f01cdc210d50001dfd8788c72c164a41bbc17a
rtf_svb_0038e7a8.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x38E7A8 962 bytes
SHA-256: dccebec6ff30f32dea492b008c7a93c18ee44b84efc33f5170556a0e447c561b
rtf_svb_0038f9ed.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x38F9ED 964 bytes
SHA-256: 65de83f9da1995ceca4030d239f160f1147ba8bc65cff69e56d96e1036f8a1f4
rtf_svb_00390a5a.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x390A5A 964 bytes
SHA-256: 39f288b305c47c2fd0fd8bd70152a78751d03b94e58ef4697d97c379caca4dee
rtf_svb_00391510.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x391510 962 bytes
SHA-256: 23b49ebcf55d2f54277e67ed137a0426cb9515e6c8114b1839bfd2e0b780ce39
rtf_svb_00392f48.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x392F48 966 bytes
SHA-256: c9a120b53568a6dad7025751988d0b74512060f8a13d1eb00a0bd65499d61adf
rtf_svb_003949e7.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x3949E7 965 bytes
SHA-256: 82c8d8674a89c4d2c1e4fd0de8103680307b4b4228464f322ce03570939e979c