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

Static analysis result for SHA-256 6331959fbc193259…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: e61a050bbf3184fae5b05bdc41ac4980 SHA-1: cd398052c407b6a534632be58b76145453b51381 SHA-256: 6331959fbc193259b1995df4d2980adcba91a78fadbfeb7c3e6728e7ce257d70
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an Excel 4.0 macro-enabled spreadsheet that leverages the Auto_Open function to execute a series of commands. It uses the CALL function to construct and execute a command that appears to download a payload from the URL https://fu5on.com/ds/231120.gif. The use of XLM macros and the ShellExecute API indicates a downloader or initial access mechanism.

Heuristics 6

  • 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.
  • 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
  • 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://fu5on.com/ds/231120.gif
    • https://fu5on.com/ds/231120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
fc23abdcb2657b335d0fb386451be5be98110592c06d0600d83d33c16e5bacb2
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6295 bytes