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

Static analysis result for SHA-256 73b667a2a90d6a1f…

MALICIOUS

Office (OLE) / .XLS

331.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 1ee484dfd5a3eb7bfc85c20f0d9c0239 SHA-1: df24ddaab9f018f90e332c6dd71519a54e5446c7 SHA-256: 73b667a2a90d6a1f9636d09299acd295ca7f587a1ac2b3f3686b422a440cfae7
242 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros that are configured to automatically execute upon opening. These macros utilize the RUN function and CALL to execute a dynamic string, which appears to be a Windows API call to load a DLL. The macro also contains a URL that is likely used to download a second-stage payload. The presence of the Auto_Open macro and the use of the RUN and CALL functions with a URL strongly indicate a downloader functionality.

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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
235e5c8d20c84fa7e893c28de1bcc715b3fa59f4feb5de8e7a84ebbe334d22cc
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6059 bytes