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

Static analysis result for SHA-256 9458b79cbd17cc0c…

MALICIOUS

Office (OLE) / .XLSX

332.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: fb67a562de1850605dc2bf58d27c824e SHA-1: b4b1697f2c165d3182e89d30576193e9b489d0e1 SHA-256: 9458b79cbd17cc0cc1d86d82ce95ad9118d78dc98d6fa190a369188a4cfdf65a
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell T1105 Ingress Tool Transfer

The file contains Excel 4.0 macros, indicated by the OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN heuristics. The SC_STR_SHELLEXEC heuristic and the embedded URL suggest that the macro is designed to download and execute a second-stage payload. The ClamAV detection further supports its malicious nature. The macro likely attempts to download a file from the provided URL.

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 http://cloud.c-tes.gr/ds/151120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
89aad7b8576d8f84c1934acd2fc0826a9bcea7c600ce1ac7e8579bafe1fef843
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 5602 bytes