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

Static analysis result for SHA-256 8d0f05e932c5eb44…

MALICIOUS

Office (OLE) / .XLS

100.3 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel
MD5: 6c76c93398a9b2a6be0c45547f11da02 SHA-1: b1f4aaf6ced83556642eb23c5158f567be81bf47 SHA-256: 8d0f05e932c5eb441dee72a078e6a95b5a3bae33429586e41eeb6f25c02d2d03
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.003 Windows Command Shell

The file is an Excel spreadsheet that exploits CVE-2009-3129, a known vulnerability in Excel's FEATHEADER record. This exploit allows for arbitrary code execution. The sample also attempts to invoke cmd.exe with an execution flag, indicating a likely attempt to download and run a second-stage payload. Several unknown URLs were extracted, suggesting a potential command and control or download source.

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 102,718 bytes but its declared streams total only 24,565 bytes — 78,153 bytes (76%) 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).
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.pdf-repair.com
    • http://www.pdf-repair.com)/Producer(Advanced
    • http://www.pdf-repair.com)/ModDate(D:20100406171120+08
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://purl.org/dc/elements/1.1/