Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a61855ee7bb4a28c…

MALICIOUS

Office (OLE)

118.5 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel First seen: 2026-05-10
MD5: 1d374ccd59977c9812130182e8d69b88 SHA-1: 74f26d3b5d27116fcdc57873d65935467ef2d698 SHA-256: a61855ee7bb4a28c220d95139de551f07baf21c631dc378cb3352608c5e3a495
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=23, isf=2, cbHdrData=4294967295). 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 121,344 bytes but its declared streams total only 24,565 bytes — 96,779 bytes (80%) 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).