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

Static analysis result for SHA-256 23b577fca11c0d75…

MALICIOUS

Office (OOXML) / .DOCX

219.5 KB Created: 2020-01-30 08:31:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2026-06-08
MD5: cf2563b769470fbb2de9e20801d12c5d SHA-1: 850ae2c127d25e55569876a4b95aca44c93206ea SHA-256: 23b577fca11c0d75ea70a3993816965c3eaefa8e76d1ded1d40422f3500edb78
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/aila.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/aila.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/aila.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/aila.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/aila.xml) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/aila.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: f57f98bd879b77916bc77c62b482d9c21f3c06497bb065bdf8d3f31321d9fdc9
objdata_01_off0011376f.bin rtf-objdata-decoded RTF \objdata at offset 0x11376F 694854 bytes
SHA-256: d09adf8f3954afd159a41e6dda82ce20629ed287663266558610b1066c08e112
rtf_svb_0038da85.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x38DA85 967 bytes
SHA-256: b461da4154fae7bb965448788af03a71a043eb99efb0e1486728dba51d84fefb
rtf_svb_0038ea29.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x38EA29 964 bytes
SHA-256: fd1e102bcb6b99544d5f496230f01cdc210d50001dfd8788c72c164a41bbc17a
rtf_svb_0038fb0c.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x38FB0C 962 bytes
SHA-256: dccebec6ff30f32dea492b008c7a93c18ee44b84efc33f5170556a0e447c561b
rtf_svb_00390d51.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x390D51 964 bytes
SHA-256: 65de83f9da1995ceca4030d239f160f1147ba8bc65cff69e56d96e1036f8a1f4
rtf_svb_00391dbe.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x391DBE 964 bytes
SHA-256: 39f288b305c47c2fd0fd8bd70152a78751d03b94e58ef4697d97c379caca4dee
rtf_svb_00392874.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x392874 962 bytes
SHA-256: 23b49ebcf55d2f54277e67ed137a0426cb9515e6c8114b1839bfd2e0b780ce39
rtf_svb_003942ac.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x3942AC 966 bytes
SHA-256: c9a120b53568a6dad7025751988d0b74512060f8a13d1eb00a0bd65499d61adf
rtf_svb_00395d4b.zip rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x395D4B 965 bytes
SHA-256: 82c8d8674a89c4d2c1e4fd0de8103680307b4b4228464f322ce03570939e979c