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

Static analysis result for SHA-256 3d88a43beb01bbb7…

MALICIOUS

Office (OLE) / .XLSX

332.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: e13f42e93d7ad6ed13302a3f5fde4418 SHA-1: ae219de8b2f73fe3587b253ba35c8e3860ec3aaf SHA-256: 3d88a43beb01bbb717df4f8e39eb15e5baed2e3cbb9d6ec07a2b11d9d3c595bd
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The file contains Excel 4.0 macros, specifically triggering the 'Auto_Open' heuristic with dangerous functions like RUN. The 'ShellExecute' API reference and the embedded URL suggest that the macro is designed to download and execute a secondary payload from the provided URL. The ClamAV detection name 'Doc.Downloader.Docusign0521-9864805-0' further supports the downloader functionality.

Heuristics 5

  • ClamAV: Doc.Downloader.Docusign0521-9864805-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Docusign0521-9864805-0
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • XLM Auto_Open with dangerous formula APIs high 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.
  • 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 https://camexsuriname.sr/ds/151120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
4d5531650e0faf8764ddd7b14e6947143c32308cbf699d36f8845764b3b4560a
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 5603 bytes