Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0f759dc956eeefaa…

MALICIOUS

Office (OLE)

110.5 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel
MD5: 0f482491dcaec8ed49d8454fae534c00 SHA-1: 8ce90119127df86aeefac2502328fa67eefddbc5 SHA-256: 0f759dc956eeefaac0fbe7ac611ddc690ed8cd6020e118157a392942b9b5c142
240 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The critical heuristic firing indicates exploitation of CVE-2009-3129, a known vulnerability in Microsoft Excel. This vulnerability allows for arbitrary code execution, likely to download and run a secondary payload. The presence of CreateProcess, LoadLibrary, and GetProcAddress API calls further supports the execution of malicious code.

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=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.
  • Reference to CreateProcess API high SC_STR_CREATEPROCESS
    Reference to CreateProcess API
  • Reference to LoadLibrary API high SC_STR_LOADLIBRARY
    Reference to LoadLibrary API
  • Reference to GetProcAddress API high SC_STR_GETPROCADDRESS
    Reference to GetProcAddress API
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 113,152 bytes but its declared streams total only 24,565 bytes — 88,587 bytes (78%) 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).
  • Reference to VirtualProtect API medium SC_STR_VIRTUALPROTECT
    Reference to VirtualProtect API