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

Static analysis result for SHA-256 614549f620b2f447…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 4a5a9e1324fecff4e4da966f450e8ccb SHA-1: dcdba570870ec707eef8353706c2eee1c6656a36 SHA-256: 614549f620b2f4473e79eb3b53b86f91d4dc66543c51648fd9fe0a543db0dd10
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059 Command and Scripting Interpreter

The file contains Excel 4.0 macros that are configured to automatically execute upon opening. These macros contain a CALL function that appears to be constructing a command to execute, and a direct reference to the URL http://fcco1936.com/ds/231120.gif, indicating it is likely a downloader for a second-stage payload. The presence of the Auto_Open macro and the use of the RUN function strongly suggest malicious intent.

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 http://fcco1936.com/ds/231120.gif
    • http://fcco1936.com/ds/231120.gif�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
1df732b478dcf2e8e2d7a8e9f6d49c0e62fe9c357edaf30cf32b9f7c844e5e47
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6297 bytes