Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 298d48ed627170aa…

MALICIOUS

Office (OLE)

37.5 KB Created: 1995-09-01 16:13:00 Authoring application: Microsoft Word 6.0 First seen: 2012-06-14
MD5: eab630e36c3287ffcc9e89bbc1910b13 SHA-1: 604e1fc8af2612f5efbb833e7a782f7b6fba15b5 SHA-256: 298d48ed627170aac517af67296982d8753149b2f02f18a5f0c13fdadced75ec
200 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The file is identified as malicious by ClamAV as Win.Trojan.Nuclear-1 and exhibits critical heuristics related to OLE document anomalies and embedded Office content. The document body describes a legacy WordBasic macro virus (WW6MACRO) that infects DOC files upon opening, aiming to spread through document sharing. The presence of 'AutoOpen' macro marker and embedded Office artifacts further supports this analysis.

Heuristics 5

  • ClamAV: Win.Trojan.Nuclear-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Nuclear-1
  • Embedded Office document has suspicious static findings critical EMBEDDED_OFFICE_CHILD_STATIC_TRIAGE
    A CFB/OLE Office document was found inside another file type and its carved contents matched Office exploit or payload heuristics. This catches wrapped exploit documents where the top-level file routes to a PE, archive, or generic scanner instead of Office.
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 38,400 bytes but its declared streams total only 19,220 bytes — 19,180 bytes (50%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • CFB header with no readable streams medium OLE_PARSE_EMPTY_STREAMS
    The file begins with a valid OLE2/CFB header but exposes no directory streams. A non-empty compound document with an unreadable directory is anomalous — it is seen with truncated/corrupt files and, more importantly, with content deliberately shifted off byte boundaries to defeat parsers while the host application still recovers the object.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_office_off00001592.ole embedded-office Embedded OLE/CFB Office body inside ole container at offset 0x1592 32878 bytes
SHA-256: 4dc0a555126b48704c44d4c7855aae22149071228f2f85e11064a7e73d574213