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

Static analysis result for SHA-256 cccd4d072383aef7…

MALICIOUS

Office (OOXML) / .DOCX

834.7 KB Created: 2025-10-14 17:40:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: abaac3711feaf738016d483ae8b07dc8 SHA-1: 5f9bd657e51e0eae86a353d5c1ba5f5663a9db06 SHA-256: cccd4d072383aef7450faf4f64bb44717ea8270a61f40657b36484283448b7b4
380 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is a Microsoft Office document that utilizes an altChunk to import an embedded RTF object. This RTF object contains OLE data and is configured to auto-update, which is a technique used to execute embedded Portable Executable (PE) files. The presence of RTF_MZ_HEX and RTF_ALTCHUNK_RTF_AUTOUPDATE_PE heuristics strongly indicates the execution of a PE file. 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/Bounty.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/Bounty.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/Bounty.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/Bounty.rtf) RTF contains ~1871KB 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/Bounty.rtf) RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    (in altChunk RTF word/Bounty.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_off000b36df.bin
7fa4c44acced4db6c4dfbc51e359da7337550b0aff1c2a07a272175a9e4a682b
rtf-objdata-decoded RTF \objdata at offset 0xB36DF 823434 bytes
objdata_01_off00250f4f.bin
24ee741dd41bc27803d80f81b66eba686fe8f5d17bd847727dc5d94834bd3188
rtf-objdata-decoded RTF \objdata at offset 0x250F4F 584826 bytes
rtf_svb_00000009.zip
4e95b2236ab77dd4a461269b1532b5bd47e69b5e448fe8c81b58db52b9ce53ec
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x9 125028 bytes
rtf_svb_00467fa8.zip
8867210384af64ad4855c4b9e2fc58516ac42c37ce1da964bc224d0027572bbb
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x467FA8 961 bytes
rtf_svb_0047b680.zip
67909526357be6cab83ebf93b9efff382ffb59d2f163f8725e5ea338c960054d
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x47B680 962 bytes
rtf_svb_0048ec95.zip
1207332480b132c745b844c92ae3305601d28183c0646e7a7e56d0ef80a1141c
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x48EC95 962 bytes
rtf_svb_004a1901.zip
c0c6e5d7f528600d0aebc43c75a3cc11f0265cb43b0c863547b4f748db8f965b
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4A1901 965 bytes
rtf_svb_004b4502.zip
c72ad9f966bba544f2082b2897fa1ff9332bd247fe634571151ef1e50412bb87
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4B4502 966 bytes
rtf_svb_004c7ae5.zip
40962420479370b700743e9c9a2b03948d708a64f382615ccb69105e740007f0
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4C7AE5 961 bytes
rtf_svb_004da757.zip
143096d1b6bcbba972d0ae293a289a35550acc7ed7d52d1fcb977fafcc3e3ba7
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4DA757 963 bytes
rtf_svb_004db186.zip
760baa8576bff65cf0596c7cb2138904918c8aeee924bf632840923db97c928a
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4DB186 966 bytes
rtf_svb_004dbf65.zip
848ccee8dd91f741c7264a38e7132ffdd34361272c7bd73c3ca92f8d95268445
rtf-svb-package RTF \svb hex-decoded ZIP at offset 0x4DBF65 963 bytes