Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 da8122fa73bb0db4…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:05 Authoring application: Microsoft Excel
MD5: ca449d113428e32de6c402d9ded43701 SHA-1: 7f13405a01faab3cd3c914b18399d2ac7586e829 SHA-256: da8122fa73bb0db4c673b4af219c4b6ecb331b86547d3619d13c91f5f1d4a48b
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 (XLM) macros, indicated by the OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN heuristics. The presence of an Auto_Open defined name suggests that the macro will execute automatically upon opening the workbook. The dangerous formula API 'RUN' is also present, which is typically used to execute arbitrary commands or download payloads. No specific URLs or hashes were extracted, but the technique strongly implies a downloader or initial execution stage.

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
23c9a15cf2b22cbd9f27ee86b4d0e99eb8a4f6f10327265313185df45ed94206
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6399 bytes