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

Static analysis result for SHA-256 49b21aea2f896ff3…

MALICIOUS

Office (OLE) / .XLS

186.6 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel
MD5: f3801a784f33a3b77e857358ace2d1f7 SHA-1: 94b84541c6e7b36b853315f21750d5088f4fa4cc SHA-256: 49b21aea2f896ff31ca31ed8e770817c17dd3120a396fcdd3254feecd49a04e4
220 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.003 Windows Command Shell

The critical CVE-2009-3129 heuristic indicates that this Excel file exploits a known vulnerability (FEATHEADER record overflow) to achieve code execution. The suspicious cmd.exe invocation suggests that the exploit is used to launch a secondary payload. The presence of unknown URLs related to 'pdf-repair.com' may indicate a lure or a command and control channel.

Heuristics 6

  • 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.
  • NOP sled detected high SC_NOP_SLED
    Found 20+ consecutive 0x90 bytes
  • 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 191,038 bytes but its declared streams total only 24,565 bytes — 166,473 bytes (87%) 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/