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

Static analysis result for SHA-256 0932bd7727a6781e…

MALICIOUS

Office (OLE) / .XLS

157.1 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel
MD5: 6240686e92fb39af32fc2e8cdaf1929d SHA-1: 67830551af30c74f18d154470daffb7532f62096 SHA-256: 0932bd7727a6781e71aa272561a6cb02572095049524e294052e096e6c428b16
220 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The critical heuristic firing for CVE-2009-3129 indicates that this Excel file exploits a record overflow vulnerability to achieve code execution. The presence of appended executable payload bytes and a suspicious cmd.exe invocation further supports this. The file likely attempts to download and execute a second-stage payload, potentially via PowerShell, given the heuristic firings.

Heuristics 5

  • 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.
  • PEB access via FS segment (x86) high SC_PEB_ACCESS
    PEB access via FS segment (x86)
  • Suspicious cmd.exe invocation with execution flag high SC_STR_CMD
    Suspicious cmd.exe invocation with execution flag
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 160,872 bytes but its declared streams total only 24,565 bytes — 136,307 bytes (85%) 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).
  • OLE file has appended executable-looking payload bytes high OLE_APPENDED_PAYLOAD
    OLE compound file contains a large high-entropy region beyond the declared major streams and that region includes shellcode, PE, or loader API markers. This is a payload-carrier signal, not a specific CVE attribution by itself.