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

Static analysis result for SHA-256 fb193543ff2aff79…

MALICIOUS

Office (OLE) / .XLSX

329.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 5e8986629bb8301629e3eb0f3e5bbdd1 SHA-1: 22e7118f1dbb2675cc081ec8162198afeee59eb3 SHA-256: fb193543ff2aff795a8c93a2a5f98ee9a09f8cf2f24d3d7bb96902168c10020b
160 Risk Score

Malware Insights

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

The presence of Excel 4.0 macros, specifically an Auto_Open macro utilizing dangerous functions like RUN, indicates a downloader. The heuristic firings for ShellExecute and XLM macros strongly suggest the execution of code to fetch and run a secondary payload. The embedded URL is likely the source of this payload.

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://bemojo.com/ds/161120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
c7e4e7ed3c1ce4a0357cad7ea2d4765567912ff9637c55ef23ac64833b3a62a6
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6274 bytes