Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 078c3b0c8304b5b5…

MALICIOUS

Office (OLE)

113.8 KB Created: 2011-05-12 09:56:45 Authoring application: Microsoft Excel First seen: 2012-07-06
MD5: a11046790a7955d2fc37cc55795c68a2 SHA-1: 27c6df3e1e161001457faa298041e897362f563e SHA-256: 078c3b0c8304b5b599787847867a882cfc0f8b983717bd001a35910ad7efebd8
100 Risk Score

Heuristics 2

  • CVE-2009-3129 — Excel FEATHEADER record overflow critical CVE exact CVE_2009_3129
    Workbook BIFF stream contains a FEATHEADER (Feature Header) record with anomalous size (record_size=22, isf=4, cbHdrData=4). Legitimate FEATHEADER records are tiny (<100 bytes) and carry cbHdrData values that fit in the record body; the value here is the documented CVE-2009-3129 exploit primitive — cbHdrData drives a memcpy with attacker-controlled size, leading to memory corruption and code execution in Excel 2007/2003.
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 116,576 bytes but its declared streams total only 29,612 bytes — 86,964 bytes (75%) 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).