Malicious Office (OLE) / .TMP — malware analysis report

Static analysis result for SHA-256 4654b8e7ef4c65b5…

MALICIOUS

Office (OLE) / .TMP

114.5 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel
MD5: 232ebc23f3392f353c8604da8f3fe9b5 SHA-1: 59986fa47307d193e95e4d798dbc0cea029aed75 SHA-256: 4654b8e7ef4c65b58ac7f55ca77462f606c0b9212f957abdc0298680abfb8e8b
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File

The sample is an OLE file with a significant amount of slack space, indicating potential obfuscation or embedded content. Crucially, it triggers a critical heuristic for CVE-2009-3129, a known vulnerability in Microsoft Excel related to FEATHEADER record overflow. This strongly suggests the file is designed to exploit this vulnerability for initial execution.

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 117,262 bytes but its declared streams total only 24,565 bytes — 92,697 bytes (79%) 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).