Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c67844b38be5e062…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:46:12 Authoring application: Microsoft Excel
MD5: 949eec7cbec385229005e69189454d88 SHA-1: ae34bf33098663cf87bc2eed0d80a03974185ce0 SHA-256: c67844b38be5e06252ec02e8006edddbfe77ef42c5735d9b8bf5c187f57975ab
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, which is a common technique for executing malicious code upon opening the document. The use of dangerous formula APIs like RUN suggests the macro is designed to download and execute a second-stage payload, although the specific URL or payload is not directly extractable from the provided evidence.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
fb2538dff799c43e51f06955383eac0213aadcd2c997a5be7caf13559b80d7d5
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6515 bytes