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

Static analysis result for SHA-256 bac6e964e37bf4ad…

MALICIOUS

Office (OOXML) / .DOCX

780.9 KB Created: 2025-10-22 14:54:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: 05b5126187c65900116a9ee440ca39a0 SHA-1: f30318f23d658b17e5b5a64e5ff6449d84477d4d SHA-256: bac6e964e37bf4adcd9f670aad4e030f6ee68dadac7c03b417e091a54f3553de
380 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1027 Obfuscated Files or Information T1140 Deobfuscate/Decode Files or Information

The OOXML document utilizes an altChunk to import an RTF object, which in turn contains OLE objects and excessive hex data. Crucially, this RTF object includes a PE executable header and is configured to auto-update, indicating a clear intent to deliver and execute a payload. The external relationship points to a template file, suggesting a potential delivery vector.

Heuristics 10

  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    (in altChunk RTF word/Fetchpr.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.
  • PE header (with DOS stub) in hex data critical RTF_MZ_HEX
    (in altChunk RTF word/Fetchpr.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/Fetchpr.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/Fetchpr.rtf) RTF contains ~1673KB 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/Fetchpr.rtf) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/Fetchpr.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://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 12

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000af6e7.bin
b11a1af0a706e39645286541c14bf4995762e7c6cdcbd07be5e867ed40fcb478
rtf-objdata-decoded RTF \objdata at offset 0xAF6E7 732906 bytes
objdata_01_off00220c17.bin
24ee741dd41bc27803d80f81b66eba686fe8f5d17bd847727dc5d94834bd3188
rtf-objdata-decoded RTF \objdata at offset 0x220C17 584826 bytes
rtf_svb_00000009.zip
8a5df68dacbb2a8c8cafa0cec2075f74c897ac52eb29c930e94be7551fac9642
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x9 116840 bytes
rtf_svb_00437c70.zip
8867210384af64ad4855c4b9e2fc58516ac42c37ce1da964bc224d0027572bbb
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x437C70 961 bytes
rtf_svb_0044b348.zip
67909526357be6cab83ebf93b9efff382ffb59d2f163f8725e5ea338c960054d
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x44B348 962 bytes
rtf_svb_0045e95d.zip
1207332480b132c745b844c92ae3305601d28183c0646e7a7e56d0ef80a1141c
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x45E95D 962 bytes
rtf_svb_004715c9.zip
c0c6e5d7f528600d0aebc43c75a3cc11f0265cb43b0c863547b4f748db8f965b
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4715C9 965 bytes
rtf_svb_004841ca.zip
c72ad9f966bba544f2082b2897fa1ff9332bd247fe634571151ef1e50412bb87
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4841CA 966 bytes
rtf_svb_004977ad.zip
40962420479370b700743e9c9a2b03948d708a64f382615ccb69105e740007f0
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4977AD 961 bytes
rtf_svb_004aa41f.zip
143096d1b6bcbba972d0ae293a289a35550acc7ed7d52d1fcb977fafcc3e3ba7
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4AA41F 963 bytes
rtf_svb_004aae4e.zip
760baa8576bff65cf0596c7cb2138904918c8aeee924bf632840923db97c928a
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4AAE4E 966 bytes
rtf_svb_004abc2d.zip
848ccee8dd91f741c7264a38e7132ffdd34361272c7bd73c3ca92f8d95268445
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4ABC2D 963 bytes